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NORTHERN FUNDS PROSPECTUS

EQUITY FUNDS

GLOBAL TACTICAL ASSET ALLOCATION FUND

Shares Class (BBALX)

INCOME EQUITY FUND

Shares Class (NOIEX)

INTERNATIONAL EQUITY FUND

Shares Class (NOIGX)

LARGE CAP CORE FUND

Shares Class (NOLCX)

LARGE CAP VALUE FUND

Shares Class (NOLVX)

SMALL CAP VALUE FUND

Shares Class (NOSGX)

SMALL CAP CORE FUND

Class I (NSGRX)

Class K (NSCKX)

U.S. QUALITY ESG FUND

Class I (NUEIX)

Class K (NUESX)

EQUITY INDEX FUNDS

EMERGING MARKETS EQUITY INDEX FUND

Shares Class (NOEMX)

GLOBAL REAL ESTATE INDEX FUND

Shares Class (NGREX)

INTERNATIONAL EQUITY INDEX FUND

Shares Class (NOINX)

MID CAP INDEX FUND

Shares Class (NOMIX)

SMALL CAP INDEX FUND

Shares Class (NSIDX)

STOCK INDEX FUND

Shares Class (NOSIX)

GLOBAL SUSTAINABILITY INDEX FUND

Class I (NSRIX)

Class K (NSRKX)

FIXED INCOME FUNDS

BOND INDEX FUND

Shares Class (NOBOX)

CORE BOND FUND

Shares Class (NOCBX)

FIXED INCOME FUND

Shares Class (NOFIX)

HIGH YIELD FIXED INCOME FUND

Shares Class (NHFIX)

SHORT BOND FUND

Shares Class (BSBAX)

LIMITED TERM U.S. GOVERNMENT FUND (formerly known as Short-Intermediate U.S. Government Fund)

Shares Class (NSIUX)

TAX-ADVANTAGED ULTRA-SHORT FIXED INCOME FUND

Shares Class (NTAUX)

ULTRA-SHORT FIXED INCOME FUND

Shares Class (NUSFX)

U.S. GOVERNMENT FUND

Shares Class (NOUGX)

U.S. TREASURY INDEX FUND

Shares Class (BTIAX)

TAX-EXEMPT FIXED INCOME FUNDS

ARIZONA TAX-EXEMPT FUND

Shares Class (NOAZX)

CALIFORNIA INTERMEDIATE TAX-EXEMPT FUND

Shares Class (NCITX)

CALIFORNIA TAX-EXEMPT FUND

Shares Class (NCATX)

HIGH YIELD MUNICIPAL FUND

Shares Class (NHYMX)

INTERMEDIATE TAX-EXEMPT FUND

Shares Class (NOITX)

LIMITED TERM TAX-EXEMPT FUND (formerly known as Short-Intermediate Tax-Exempt Fund)

Shares Class (NSITX)

TAX-EXEMPT FUND

Shares Class (NOTEX)

ACTIVE M/MULTI-MANAGER FUNDS

ACTIVE M EMERGING MARKETS EQUITY FUND

Shares Class (NMMEX)

ACTIVE M INTERNATIONAL EQUITY FUND

Shares Class (NMIEX)

MULTI-MANAGER EMERGING MARKETS DEBT OPPORTUNITY FUND

Shares Class (NMEDX)

MULTI-MANAGER GLOBAL LISTED INFRASTRUCTURE FUND

Shares Class (NMFIX)

MULTI-MANAGER GLOBAL REAL ESTATE FUND

Shares Class (NMMGX)

MULTI-MANAGER HIGH YIELD OPPORTUNITY FUND

Shares Class (NMHYX)

NORTHERN ENGAGE360^TM FUND

Shares Class (NENGX)

Prospectus dated July 29, 2022

An investment in a Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (“FDIC”), any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank. An investment in a Fund involves investment risks, including possible loss of principal.

The Securities and Exchange Commission (“SEC”) has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

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FUND SUMMARIES

GLOBAL TACTICAL ASSET ALLOCATION FUND

INVESTMENT OBJECTIVE

The Fund seeks to provide long-term capital appreciation and current income.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares Class shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 60.88% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

The Fund will generally seek exposure to a number of different asset classes based on an asset allocation framework developed by the Investment Policy Committee of The Northern Trust Company (“TNTC”) and NTI (TNTC and NTI are collectively referred to herein as “Northern Trust”). The asset classes in which the Fund seeks to obtain exposure include but are not limited to small-, mid- and large-capitalization common stocks; real estate securities; commodity-related securities; and fixed-income securities, including high yield securities and money market instruments. The Fund primarily obtains exposure to these asset classes by investing in shares of underlying mutual funds and exchange-traded funds (“ETFs”), including mutual funds and ETFs for which NTI, the Fund’s investment adviser, or an affiliate acts as investment adviser (collectively, “Underlying Funds”). The Fund also may obtain exposure to one or more asset classes by investing directly in equity or fixed-income securities or money market instruments. In addition, the Fund also may invest directly in derivatives, including but not limited to forward foreign currency exchange contracts, futures contracts and options on futures contracts, for hedging purposes.

The Fund may obtain exposure to securities of U.S. and foreign issuers, including those in emerging markets countries (i.e., those that are generally in the early stages of their industrial cycles). The Fund expects its foreign exposure to be allocated among various regions or countries, including the United States (but in no less than three different countries).

Northern Trust’s Investment Policy Committee is responsible for developing tactical asset allocation recommendations with

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respect to the Fund using the asset allocation framework and incorporating various criteria, including, for example, economic factors such as gross domestic product and inflation; fixed-income market factors such as sovereign yields, credit spreads and currency trends; and equity market factors such as domestic and foreign operating earnings and valuation levels. NTI monitors the Fund daily to ensure it is invested pursuant to the current asset allocation framework. NTI reviews the asset allocation framework and recommended allocations at least monthly, or more frequently as needed, to consider adjusting the allocations based on its evolving investment views amid changing market and economic conditions. There is no limit in the number of Underlying Funds in which the Fund may invest. The Fund is not required to maintain any minimum or maximum investment in any asset class.

From time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular sectors. As of March 31, 2022, the Fund had a focused investment in the information technology sector.

NTI may engage in active trading, and will not consider portfolio turnover a limiting factor in making decisions for the Fund.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

Because the Fund invests primarily in the Underlying Funds, the risks described below are in reference to the Underlying Funds, and to the extent that the Fund invests directly in securities and other instruments, the risks described below are also directly applicable to the Fund.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets. Market risk includes the risk that a particular style of investing, such as growth or value, may underperform the market generally.

ASSET ALLOCATION RISK is the risk that the selection by a manager of the Underlying Funds and the allocation of the Fund’s assets among the various asset classes and market segments will not perform as expected. The Fund’s investment in any one Underlying Fund or asset class may exceed 15% of the Fund’s total assets, which may cause it to be subject to greater volatility and risk than a more diversified fund.

UNDERLYING FUND RISK is the risk that the Fund’s investment performance and its ability to achieve its investment objective are directly related to the performance of the Underlying Funds in which it invests. There can be no assurance that the Underlying Funds will achieve their respective investment objectives. The Fund will be subject to the risks associated with investments in the Underlying Funds, such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. In addition, passively managed Underlying Funds may not track the performance of their respective reference assets and may hold troubled securities or other investments. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Fund indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. Further, investments in ETFs are subject to the following additional risks: (1) an ETF’s shares may trade above or below its net asset value; (2) an active trading market for the ETF’s shares may not develop or be maintained; and (3) trading an ETF’s shares may be halted by the listing exchange. The Fund is subject to the risks of the Underlying Funds in direct proportion to the allocation of its assets among the Underlying Funds.

FOREIGN SECURITIES RISK is the risk that investing in foreign (non-U.S.) securities may result in the Fund experiencing more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies, due to less liquid markets, and adverse economic, political, diplomatic, financial, and regulatory factors. Foreign governments may impose limitations on foreigners’ ownership of interests in local issuers, restrictions on the ability to repatriate assets, and may also impose taxes. Any of these events could cause the value of the Fund’s investments to decline. Foreign banks, agents and

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securities depositories that hold the Fund’s foreign assets may be subject to little or no regulatory oversight over, or independent evaluation, of their operations. Additional costs associated with investments in foreign securities may include higher custodial fees than those applicable to domestic custodial arrangements and transaction costs of foreign currency conversions. Unless the Fund has hedged its foreign currency exposure, foreign securities risk also involves the risk of negative foreign currency rate fluctuations, which may cause the value of securities denominated in such foreign currency (or other instruments through which the Fund has exposure to foreign currencies) to decline in value. Currency exchange rates may fluctuate significantly over short periods of time. Currency hedging strategies, if used, are not always successful. For instance, forward foreign currency exchange contracts, if used by the Fund, could reduce performance if there are unanticipated changes in currency exchange rates.

EMERGING MARKETS RISK is the risk that emerging markets are generally subject to greater market volatility, political, social and economic instability, uncertain trading markets and more governmental limitations on foreign investments than more developed markets. In addition, companies operating in emerging markets may be subject to lower trading volumes and greater price volatility than companies in more developed markets. Emerging market economies may be based on only a few industries, may be highly vulnerable to changes in local and global trade conditions, and may suffer from extreme and volatile debt burdens or inflation rates. Companies in emerging market countries generally may be subject to less stringent regulatory, disclosure, financial reporting, accounting, auditing and recordkeeping standards than companies in more developed countries. As a result, information, including financial information, about such companies may be less available and reliable, which can impede the Fund’s ability to evaluate such companies. Securities law and the enforcement of systems of taxation in many emerging market countries may change quickly and unpredictably, and the ability to bring and enforce actions (including bankruptcy, confiscatory taxation, expropriation, nationalization of a company’s assets, restrictions on foreign ownership of local companies, restrictions on withdrawing assets from the country, protectionist measures and practices such as share blocking), or to obtain information needed to pursue or enforce such actions, may be limited. Investments in emerging market securities may be subject to additional transaction costs, delays in settlement procedures, unexpected market closures, and lack of timely information.

INVESTMENT STYLE RISK is the risk that different investment styles (e.g., “growth”, “value” or “quantitative”) tend to shift in and out of favor, depending on market and economic conditions as well as investor sentiment. The Fund may outperform or underperform other funds that invest in similar asset classes but employ a different investment style. The Fund may also employ a combination of styles that impacts its risk characteristics.

MANAGEMENT RISK is the risk that a strategy used by the Fund’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.

COMMODITY-RELATED SECURITIES RISK is the risk that exposure to the commodities markets may subject the Fund to greater volatility than investments in other kinds of securities. In addition to overall market movements, commodity-related securities may be adversely impacted by commodity index volatility, changes in interest rates, or factors affecting a particular industry or commodity, such as weather, disease (including pandemic), tariffs, embargoes or other trade barriers, acts of war or terrorism, or political and regulatory developments.

CREDIT (OR DEFAULT) RISK is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations will adversely affect the value of the Fund’s investments and its returns. The credit quality of a debt security or of the issuer of a debt security held by the Fund could deteriorate rapidly, which may impair the Fund’s liquidity or cause a deterioration in the Fund’s NAV. The Fund could also be delayed or hindered in its enforcement of rights against an issuer, guarantor or counterparty.

DEBT EXTENSION RISK is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Fund later than expected. This will cause the value of the security, and the Fund’s NAV, to decrease, and the Fund may lose opportunities to invest in higher yielding securities.

DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and

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leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

GEOGRAPHIC RISK is the risk that if an Underlying Fund invests a significant portion of its total assets in certain issuers within the same country or geographic region, an adverse economic, business or political development affecting that country or region may affect the value of the Fund’s investments more, and the Fund’s investments may be more volatile, than if the Underlying Fund’s investments were not so concentrated in such country or region.

SECTOR RISK is the risk that companies in similar businesses may be similarly affected by particular economic or market events, which may, in certain circumstances, cause the value of securities of all companies in a particular sector of the market to decrease.

HIGH-YIELD RISK is the risk that the Fund’s below-investment grade fixed-income securities, sometimes known as “junk bonds,” will be subject to greater credit risk, price volatility and risk of loss than investment grade securities, which can adversely impact the Fund’s return and NAV. High yield securities are considered highly speculative and are subject to the increased risk of an issuer’s inability to make principal and interest payments.

INTEREST RATE RISK is the risk that during periods of rising interest rates, the Fund’s yield (and the market value of its securities) will tend to be lower than prevailing market rates; in periods of falling interest rates, the Fund’s yield (and the market value of its securities) will tend to be higher. In general, securities with longer maturities or durations are more sensitive to interest rate changes. Risks associated with rising interest rates are heightened given that interest rates in the U.S. are currently at low levels. Changing interest rates, including rates that fall below zero, may have unpredictable effects on the markets and the Fund’s investments, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Fund, and may detract from Fund performance. A low or negative interest rate environment could cause the Fund’s earnings to fall below the Fund’s expense ratio, resulting in a low or negative yield and a decline in the Fund’s NAV. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Fund.

SMALL AND MID CAP STOCK RISK is the risk that stocks of small and mid-sized companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Small and mid-sized companies may have limited product lines or financial resources, and may be dependent upon a particular niche of the market. The securities of small companies may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally, the smaller the company size, the greater the risk.

PREPAYMENT (OR CALL) RISK is the risk that an issuer could exercise its right to pay principal on callable debt securities held by the Fund earlier than expected. Issuers may be more likely to

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prepay when interest rates fall, when credit spreads change, or when an issuer’s credit quality improves. If this happens, the Fund will not benefit from the rise in the market price of the securities that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds in lower yielding securities, which may reduce the Fund’s returns. The Fund may also lose any premium it paid to purchase the securities.

REAL ESTATE SECURITIES RISK is the risk that investments in real estate investment trusts (“REITs”) and securities of real estate companies will make the Fund more susceptible to risks associated with the ownership of real estate and with the real estate industry in general. These risks include possible declines in the value of real estate, possible lack of mortgage funds and unexpected vacancies of properties, increases in property taxes, fluctuations in interest rates and limited availability of mortgage financing. REITs that invest in real estate mortgages are also subject to prepayment risks. REITs and real estate companies may be less diversified than other pools of securities, may have lower trading volumes and may be subject to more abrupt or erratic price movements than the overall securities markets.

U.S. GOVERNMENT SECURITIES RISK is the risk that the U.S. government will not provide financial support to its agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. Certain U.S. government securities purchased by the Fund are neither issued nor guaranteed by the U.S. Treasury and, therefore, may not be backed by the full faith and credit of the United States. The maximum potential liability of the issuers of some U.S. government securities may greatly exceed their current resources, including any legal right to support from the U.S. Treasury. It is possible that the issuers of such securities will not have the funds to meet their payment obligations in the future.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compares to those of two broad-based securities market indices and to a custom blended benchmark that reflect the investment instruments in which the Fund invests.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Updated performance information for the Fund is available and may be obtained on the Trust’s website at northerntrust.com/funds or by calling 800-595-9111.

CALENDAR YEAR TOTAL RETURN*

* Year to date total return for the six months ended June 30, 2022 was (13.73)%. For the periods shown in the bar chart above, the highest quarterly return was 12.55% in the second quarter of 2020, and the lowest quarterly return was (16.81)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2021)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds.

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MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the Global Tactical Asset Allocation Fund. James D. McDonald, Executive Vice President of NTI, and Daniel J. Phillips, CFA, Senior Vice President of NTI, Christopher Shipley, Senior Vice President of NTI, and Timothy Johnson, Senior Vice President of NTI have been managers of the Fund (including the Predecessor Fund) since July 2014, April 2011 and July 2022, respectively. The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

PURCHASE AND SALE OF FUND SHARES

You may purchase Shares Class shares of the Fund by opening an account directly with Northern Funds (the “Trust”) with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums. You may also purchase Shares Class shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary.

If you purchase, sell (redeem) or exchange Shares Class shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

TAX INFORMATION

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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INCOME EQUITY FUND

INVESTMENT OBJECTIVE

The Fund seeks to provide a high level of current income and long-term capital appreciation.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares Class shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 30.55% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

In seeking to achieve its investment objective, the Fund will, under normal circumstances, invest at least 80% of its net assets in income-producing equity securities, including dividend-paying common and preferred stocks. The Fund seeks to provide a high level of current income relative to other mutual funds that invest in equity securities.

In determining capital appreciation potential, NTI uses a proprietary quantitative ranking system that is designed to provide exposure to equity securities that exhibit quality characteristics. Beginning with a broad universe of highly liquid equity securities, NTI applies a proprietary quality score, which ranks each security based on its issuer’s profitability, management efficiency, and cash generation, to screen out the lowest quality securities based on their proprietary ranking. NTI then selects securities from the remaining universe that it believes will achieve the appropriate quality and yield exposures. NTI also performs a risk management analysis in which NTI seeks to measure and manage risk exposures at the security, sector and portfolio levels through portfolio diversification. Final purchase decisions are made based on the desired level of diversification and dividend yield.

The Fund may use derivatives such as stock index futures contracts to equitize cash and enhance portfolio liquidity. NTI will normally sell a security that it believes is no longer attractive based upon the evaluation criteria described above.

From time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular sectors. As of March 31, 2022, the Fund focused its investments in the information technology sector.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks,

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including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), yield, total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets. Market risk includes the risk that a particular style of investing, such as growth or value, may underperform the market generally.

INVESTMENT STYLE RISK is the risk that different investment styles (e.g., “growth”, “value” or “quantitative”) tend to shift in and out of favor, depending on market and economic conditions as well as investor sentiment. The Fund may outperform or underperform other funds that invest in similar asset classes but employ a different investment style. The Fund may also employ a combination of styles that impacts its risk characteristics.

MANAGEMENT RISK is the risk that a strategy used by the Fund’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.

SECTOR RISK is the risk that companies in similar businesses may be similarly affected by particular economic or market events, which may, in certain circumstances, cause the value of securities of all companies in a particular sector of the market to decrease.

DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

PREFERRED SECURITIES RISK Preferred securities are subject to issuer-specific and market risks applicable generally to equity securities. Preferred securities also may be subordinated to bonds or other debt instruments, subjecting them to a greater risk of non-payment, may be less liquid than many other securities, such as common stocks, and generally offer no voting rights with respect to the issuer.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a

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deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index.

On July 31, 2014, the Fund changed its principal investment strategy from a fundamental actively managed strategy to a quantitative actively managed strategy. The performance shown prior to that date represents performance of the Fund’s prior fundamental actively managed strategy.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Updated performance information for the Fund is available and may be obtained on the Fund’s website at northerntrust.com/funds or by calling 800-595-9111.

CALENDAR YEAR TOTAL RETURN*

* Year to date total return for the six months ended June 30, 2022 was (15.97)%. For the periods shown in the bar chart above, the highest quarterly return was 19.18% in the second quarter of 2020, and the lowest quarterly return was (22.67)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2021)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the Income Equity Fund. Reed A. LeMar, CFA, Vice President of NTI and Jeffrey D. Sampson, CFA, Senior Vice President of NTI, have been managers of the Fund since July 2017, and Sridhar Kancharla, CFA, Senior Vice President of NTI, has been a manager of the Fund since July 31, 2018. The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

PURCHASE AND SALE OF FUND SHARES

You may purchase Shares Class shares of the Fund by opening an account directly with Northern Funds (the “Trust”) with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums. You may also purchase Shares Class shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary.

If you purchase, sell (redeem) or exchange Shares Class shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth

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above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

TAX INFORMATION

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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INTERNATIONAL EQUITY FUND

INVESTMENT OBJECTIVE

The Fund seeks to provide long-term capital appreciation. Any income received is incidental to this objective.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares Class shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 41.96% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

In seeking long-term capital appreciation, the Fund will invest, under normal circumstances, at least 80% of its net assets in equity securities. Under normal circumstances, the Fund will invest significantly (at least 40%) in the securities of companies that are located, headquartered, incorporated or otherwise organized outside of the United States. These companies generally have market capitalizations in excess of $1 billion. The Fund may invest up to 25% of its total assets in emerging markets.

The Fund’s investment strategy attempts to create a portfolio with similar risk, style, capitalization and industry characteristics as the MSCI World^® ex USA Index with the potential to provide excess returns by allowing the Fund to hold a portion, but not all of the securities in the MSCI World ex USA Index. In managing the Fund, NTI attempts to achieve the Fund’s objective by overweighting those stocks that it believes will outperform the MSCI World ex USA Index and underweighting (or excluding entirely) those stocks that it believes will underperform the MSCI World ex USA Index. The Fund seeks to accomplish this goal by employing a strategy that uses statistics and advanced econometric methods to evaluate fundamental and quantifiable stock or firm characteristics (such as relative valuation, price momentum and earnings quality). The characteristics are combined to create a proprietary multifactor quantitative stock selection model that generates stock specific forecasts that are used along with controls intended to manage risk to determine security weightings.

The Fund may use derivatives such as stock index futures contracts to equitize cash and enhance portfolio liquidity. NTI will normally sell a security that it believes is no longer attractive based upon the evaluation criteria described above.

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INTERNATIONAL EQUITY FUND

From time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular countries or geographic regions. As of March 31, 2022, the Fund focused its investments in the financial and industrials sectors and in Japan.

NTI may engage in active trading, and will not consider portfolio turnover a limiting factor in making decisions for the Fund.

MSCI Inc. does not endorse any of the securities in the MSCI World ex USA Index. It is not a sponsor of the International Equity Fund and is not affiliated with the Fund in any way.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets. Market risk includes the risk that a particular style of investing, such as growth or value, may underperform the market generally.

MID CAP STOCK RISK is the risk that stocks of mid-sized companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Mid-sized companies may have limited product lines or financial resources, and may be dependent upon a particular niche of the market.

FOREIGN SECURITIES RISK is the risk that investing in foreign (non-U.S.) securities may result in the Fund experiencing more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies, due to less liquid markets and adverse economic, political, diplomatic, financial, and regulatory factors. Foreign governments may impose limitations on foreigners’ ownership of interests in local issuers, restrictions on the ability to repatriate assets, and may also impose taxes. Any of these events could cause the value of the Fund’s investments to decline. Foreign banks, agents and securities depositories that hold the Fund’s foreign assets may be subject to little or no regulatory oversight over, or independent evaluation, of their operations. Additional costs associated with investments in foreign securities may include higher custodial fees than those applicable to domestic custodial arrangements and transaction costs of foreign currency conversions. Unless the Fund has hedged its foreign currency exposure, foreign securities risk also involves the risk of negative foreign currency rate fluctuations, which may cause the value of securities denominated in such foreign currency (or other instruments through which the Fund has exposure to foreign currencies) to decline in value. Currency exchange rates may fluctuate significantly over short periods of time. Currency hedging strategies, if used, are not always successful. For instance, forward foreign currency exchange contracts, if used by the Fund, could reduce performance if there are unanticipated changes in currency exchange rates.

INVESTMENT STYLE RISK is the risk that different investment styles (e.g., “growth”, “value” or “quantitative”) tend to shift in and out of favor, depending on market and economic conditions as well as investor sentiment. The Fund may outperform or underperform other funds that invest in similar asset classes but employ a different investment style. The Fund may also employ a combination of styles that impacts its risk characteristics.

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MANAGEMENT RISK is the risk that a strategy used by the Fund’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.

GEOGRAPHIC RISK is the risk that if the Fund invests a significant portion of its total assets in certain issuers within the same country or geographic region, an adverse economic, business or political development affecting that country or region may affect the value of the Fund’s investments more, and the Fund’s investments may be more volatile, than if its investments were not so concentrated in such country or region.

SECTOR RISK is the risk that companies in similar businesses may be similarly affected by particular economic or market events, which may, in certain circumstances, cause the value of securities of all companies in a particular sector of the market to decrease.

DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

VALUATION RISK is the risk that the sale price the Fund could receive for a portfolio security may differ from the Fund’s valuation of the security, particularly for securities that trade in low volume or volatile markets or that are valued using a fair value methodology. In addition, the value of the securities in the Fund’s portfolio may change on days when shareholders will not be able to purchase or sell the Fund’s shares.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index.

On January 1, 2017, the Fund changed its principal investment strategy from a fundamental actively managed strategy to a quantitative actively managed strategy. The performance shown prior to that date represents performance of the Fund’s prior fundamental actively managed strategy.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Updated performance information for the Fund is available and may be obtained on the Fund’s website at northerntrust.com/funds or by calling 800-595-9111.

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INTERNATIONAL EQUITY FUND

CALENDAR YEAR TOTAL RETURN*

* Year to date total return for the six months ended June 30, 2022 was (17.17)%. For the periods shown in the bar chart above, the highest quarterly return was 14.65% in the fourth quarter of 2020, and the lowest quarterly return was (25.00)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2021)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the International Equity Fund. Michael R. Hunstad, Senior Vice President of NTI and Mark C. Sodergren, CFA, Senior Vice President of NTI, have been managers of the Fund since July 2019 and January 2017, respectively. The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

PURCHASE AND SALE OF FUND SHARES

You may purchase Shares Class shares of the Fund by opening an account directly with Northern Funds (the “Trust”) with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums.

You may also purchase Shares Class shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary. If you purchase, sell (redeem) or exchange Shares Class shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

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INTERNATIONAL EQUITY FUND

TAX INFORMATION

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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LARGE CAP CORE FUND

INVESTMENT OBJECTIVE

The Fund seeks long-term growth of capital. Any income received is incidental to this objective.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares Class shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 44.93% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

In seeking its investment objective, the Fund will invest, under normal circumstances, at least 80% of its net assets in a broadly diversified portfolio of equity securities in large capitalization U.S. companies, including foreign issuers that are traded in the U.S. Large capitalization companies generally are considered to be those whose market capitalization is, at the time the Fund makes an investment, within the range of the market capitalization of the companies in the Russell 1000^® Index.

The Fund seeks to achieve its investment objective by employing a strategy that uses statistics and advanced econometric methods to evaluate fundamental and quantifiable stock or firm characteristics (such as relative valuation, price momentum and earnings quality). The characteristics are combined to create a proprietary multifactor quantitative stock selection model, which generates stock specific forecasts that are used along with controls intended to manage risk to determine security weightings.

The Fund may use derivatives such as stock index futures contracts to equitize cash and enhance portfolio liquidity. NTI will normally sell a security that it believes is no longer attractive based upon the evaluation criteria described above.

From time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular sectors. As of March 31, 2022, the Fund focused its investments in the information technology sector.

NTI may engage in active trading, and will not consider portfolio turnover a limiting factor in making decisions for the Fund.

Frank Russell Company does not endorse any of the securities in the Russell 1000 Index. It is not a sponsor of the Large Cap Core Fund and is not affiliated with the Fund in any way.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may

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adversely affect the Fund’s net asset value (“NAV”), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets. Market risk includes the risk that a particular style of investing, such as growth or value, may underperform the market generally.

INVESTMENT STYLE RISK is the risk that different investment styles (e.g., “growth”, “value” or “quantitative”) tend to shift in and out of favor, depending on market and economic conditions as well as investor sentiment. The Fund may outperform or underperform other funds that invest in similar asset classes but employ a different investment style. The Fund may also employ a combination of styles that impacts its risk characteristics.

MANAGEMENT RISK is the risk that a strategy used by the Fund’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.

SECTOR RISK is the risk that companies in similar businesses may be similarly affected by particular economic or market events, which may, in certain circumstances, cause the value of securities of all companies in a particular sector of the market to decrease.

DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

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LARGE CAP CORE FUND

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Updated performance information for the Fund is available and may be obtained on the Fund’s website at northerntrust.com/funds or by calling 800-595-9111.

CALENDAR YEAR TOTAL RETURN*

* Year to date total return for the six months ended June 30, 2022 was (18.18)%. For the periods shown in the bar chart above, the highest quarterly return was 20.05% in the second quarter of 2020, and the lowest quarterly return was (21.23)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2021)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the Large Cap Core Fund. Michael R. Hunstad, Senior Vice President of NTI and Mark C. Sodergren, CFA, Senior Vice President of NTI, have been managers of the Fund since July 2019 and July 2011, respectively. The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

PURCHASE AND SALE OF FUND SHARES

You may purchase Shares Class shares of the Fund by opening an account directly with Northern Funds (the “Trust”) with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums. You may also purchase Shares Class shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary.

If you purchase, sell (redeem) or exchange Shares Class shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

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LARGE CAP CORE FUND

TAX INFORMATION

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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LARGE CAP VALUE FUND

INVESTMENT OBJECTIVE

The Fund seeks to provide long-term capital appreciation.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares Class shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 75.05% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

In seeking long-term capital appreciation, the Fund will invest, under normal circumstances, at least 80% of its net assets in equity securities of large capitalization companies. Large capitalization companies generally are considered to be those whose market capitalization is, at the time the Fund makes an investment, within the range of the market capitalization of the companies in the Russell 1000^® Value Index. Companies whose capitalization no longer meets this definition after purchase may continue to be considered large capitalization companies.

In buying stocks, NTI uses a quantitatively managed strategy designed to provide exposure to value and quality factors. Beginning with a broad universe of highly liquid equity securities, NTI seeks to identify those securities that are out-of-favor and undervalued by applying a proprietary value screen. Once the targeted universe of value securities has been identified, NTI applies a proprietary quality score to rank each security to eliminate the lowest quality securities based on their proprietary ranking. NTI then selects securities from the remaining universe that it believes will achieve the appropriate capitalization and diversification goals, while focusing on those value securities ranking in the top quintile based on their proprietary quality and value score. NTI also performs a risk management analysis in which NTI seeks to measure and manage risk exposures at the security, sector, region and portfolio levels through portfolio diversification. Final purchase decisions are made based on a fundamental review of the remaining companies and on the desired level of diversification.

The Fund may use derivatives such as stock index futures contracts to equitize cash and enhance portfolio liquidity. NTI will normally sell a security that it believes is no longer attractive based upon the evaluation criteria described above.

From time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular sectors. As of March 31, 2022, the Fund focused its investments in the financial and health care sectors.

NTI may engage in active trading, and will not consider portfolio turnover a limiting factor in making decisions for the Fund.

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LARGE CAP VALUE FUND

Frank Russell Company does not endorse any of the securities in the Russell 1000 Value Index. It is not a sponsor of the Large Cap Value Fund and is not affiliated with the Fund in any way.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets. Market risk includes the risk that a particular style of investing, such as growth or value, may underperform the market generally.

INVESTMENT STYLE RISK is the risk that different investment styles (e.g., “growth”, “value” or “quantitative”) tend to shift in and out of favor, depending on market and economic conditions as well as investor sentiment. The Fund may outperform or underperform other funds that invest in similar asset classes but employ a different investment style. The Fund may also employ a combination of styles that impacts its risk characteristics.

MANAGEMENT RISK is the risk that a strategy used by the Fund’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.

SECTOR RISK is the risk that companies in similar businesses may be similarly affected by particular economic or market events, which may, in certain circumstances, cause the value of securities of all companies in a particular sector of the market to decrease.

DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly

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LARGE CAP VALUE FUND

specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index.

On July 31, 2014, the Fund changed its principal investment strategy from a fundamental actively managed strategy to a quantitative actively managed strategy. The performance shown prior to that date represents performance of the Fund’s prior fundamental actively managed strategy.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Updated performance information for the Fund is available and may be obtained on the Fund’s website at northerntrust.com/funds or by calling 800-595-9111.

CALENDAR YEAR TOTAL RETURN*

* Year to date total return for the six months ended June 30, 2022 was (12.14)%. For the periods shown in the bar chart above, the highest quarterly return was 17.68% in the fourth quarter of 2020, and the lowest quarterly return was (29.04)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2021)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the Large Cap Value Fund. Mark C. Sodergren, CFA, Senior Vice President of NTI and Sridhar Kancharla, CFA, Senior Vice President of NTI, have been managers of the Fund since June 2014 and July 2015, respectively. The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

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LARGE CAP VALUE FUND

PURCHASE AND SALE OF FUND SHARES

You may purchase Shares Class shares of the Fund by opening an account directly with Northern Funds (the “Trust”) with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums. You may also purchase Shares Class shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary.

If you purchase, sell (redeem) or exchange Shares Class shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

TAX INFORMATION

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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SMALL CAP VALUE FUND

INVESTMENT OBJECTIVE

The Fund seeks to provide long-term capital appreciation. Any income received is incidental to this objective.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares Class shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 20.41% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

In seeking long-term capital appreciation, the Fund will invest, under normal circumstances, at least 80% of its net assets in equity securities of small capitalization companies. Small capitalization companies generally are considered to be those whose market capitalization is, at the time the Fund makes an investment, within the range of the market capitalization of companies in the Russell 2000^® Value Index. Companies whose capitalization no longer meets this definition after purchase may continue to be considered small capitalization companies.

Using a quantitative analysis to evaluate financial data, NTI buys small capitalization stocks of companies believed to be worth more than is indicated by current market prices. Similarly, the management team normally will sell a security that it believes has achieved its full valuation, is not attractively priced or for other reasons. The team also may sell securities in order to maintain the desired portfolio characteristics of the Fund. In determining whether a stock is attractively priced, the Fund employs a strategy that uses statistics and other methods to evaluate fundamental and quantifiable stock or firm characteristics (such as relative valuation, price momentum and earnings quality). The characteristics are combined to create a proprietary multi-factor quantitative stock selection model that generates stock specific forecasts that are used along with controls intended to manage risk to determine security weightings.

Many of the companies in which the Fund invests retain their earnings to finance current and future growth. These companies generally pay little or no dividends.

The Fund may use derivatives such as stock index futures contracts to equitize cash and enhance portfolio liquidity.

From time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular sectors. As of March 31, 2022, the Fund focused its investments in the financial and industrials sectors.

Frank Russell Company does not endorse any of the securities in the Russell 2000 Value Index. It is not a sponsor of the Small Cap Value Fund and is not affiliated with the Fund in any way.

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SMALL CAP VALUE FUND

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets. Market risk includes the risk that a particular style of investing, such as growth or value, may underperform the market generally.

SMALL CAP STOCK RISK is the risk that stocks of smaller companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Small companies may have limited product lines or financial resources, or may be dependent upon a small or inexperienced management group, and their securities may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally, the smaller the company size, the greater the risk.

INVESTMENT STYLE RISK is the risk that different investment styles (e.g., “growth”, “value” or “quantitative”) tend to shift in and out of favor, depending on market and economic conditions as well as investor sentiment. The Fund may outperform or underperform other funds that invest in similar asset classes but employ a different investment style. The Fund may also employ a combination of styles that impacts its risk characteristics.

MANAGEMENT RISK is the risk that a strategy used by the Fund’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.

SECTOR RISK is the risk that companies in similar businesses may be similarly affected by particular economic or market events, which may, in certain circumstances, cause the value of securities of all companies in a particular sector of the market to decrease.

DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly

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SMALL CAP VALUE FUND

specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Updated performance information for the Fund is available and may be obtained on the Fund’s website at northerntrust.com/funds or by calling 800-595-9111.

CALENDAR YEAR TOTAL RETURN*

* Year to date total return for the six months ended June 30, 2022 was (15.49)%. For the periods shown in the bar chart above, the highest quarterly return was 27.40% in the fourth quarter of 2020, and the lowest quarterly return was (34.43)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2021)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds. Under certain circumstances, the addition of the tax benefits from capital losses resulting from redemptions may cause the Returns after taxes on distributions and sale of fund shares to be greater than the Returns after taxes on distributions or even the Returns before taxes.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the Small Cap Value Fund. Robert H. Bergson, CFA, Senior Vice President of NTI and Michael R. Hunstad, Senior Vice President of NTI, have been managers of the Fund since July 2001 and July 2020, respectively. The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

PURCHASE AND SALE OF FUND SHARES

You may purchase Shares Class shares of the Fund by opening an account directly with Northern Funds (the “Trust”) with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums. You may also purchase Shares Class shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary.

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SMALL CAP VALUE FUND

If you purchase, sell (redeem) or exchange Shares Class shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

TAX INFORMATION

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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SMALL CAP CORE FUND

INVESTMENT OBJECTIVE

The Fund seeks to provide long-term capital appreciation. Any income received is incidental to this objective.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell Class K shares or Class I shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Class K or Class I shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in Class K shares and Class I shares of the

Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your Class K shares or Class I shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 15.47% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

In seeking long-term capital appreciation, the Fund will invest, under normal circumstances, at least 80% of its net assets in equity securities of small capitalization companies. Small capitalization companies generally are considered to be those whose market capitalization is, at the time the Fund makes an investment, within the range of the market capitalization of companies in the Russell 2000^® Index. Companies whose capitalization no longer meets this definition after purchase may continue to be considered small capitalization companies.

Using a quantitative analysis to evaluate financial data, NTI buys securities of small capitalization companies that it believes have favorable characteristics such as earnings quality and/or competitive returns on equity relative to their peers. The team may sell securities in order to maintain the desired portfolio characteristics of the Fund. In determining whether a company has favorable characteristics, NTI uses an evaluation process that includes, but is not limited to:

NTI also performs a risk management analysis in which NTI seeks to measure and manage risk exposures at the security, sector and portfolio levels through portfolio diversification. Final purchase decisions are made based on a quantitative review of each company and on the desired level of diversification.

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SMALL CAP CORE FUND

Many of the companies in which the Fund invests retain their earnings to finance current and future growth. These companies generally pay little or no dividends. The Fund may use derivatives such as stock index futures contracts to equitize cash and enhance portfolio liquidity.

From time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular sectors. As of March 31, 2022, the Fund focused its investments in the financial, industrials and health care sectors.

NTI may engage in active trading, and will not consider portfolio turnover a limiting factor in making decisions for the Fund.

Frank Russell Company does not endorse any of the securities in the Russell 2000 Index. It is not a sponsor of the Small Cap Core Fund and is not affiliated with the Fund in any way.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets. Market risk includes the risk that a particular style of investing, such as growth or value, may underperform the market generally.

SMALL CAP STOCK RISK is the risk that stocks of smaller companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Small companies may have limited product lines or financial resources, or may be dependent upon a small or inexperienced management group, and their securities may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally, the smaller the company size, the greater the risk.

INVESTMENT STYLE RISK is the risk that different investment styles (e.g., “growth”, “value” or “quantitative”) tend to shift in and out of favor, depending on market and economic conditions as well as investor sentiment. The Fund may outperform or underperform other funds that invest in similar asset classes but employ a different investment style. The Fund may also employ a combination of styles that impacts its risk characteristics.

MANAGEMENT RISK is the risk that a strategy used by the Fund’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.

SECTOR RISK is the risk that companies in similar businesses may be similarly affected by particular economic or market events, which may, in certain circumstances, cause the value of securities of all companies in a particular sector of the market to decrease.

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SMALL CAP CORE FUND

DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing: (A) changes in the performance of the Fund from year to year and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index.

The returns shown for periods ended prior to July 31, 2020 are those of the Shares Class shares of the Fund at net asset value. Effective July 31, 2020, Shares Class shares of the Fund were converted into new Class K shares and Class I shares of the Fund. Class K and Class I shares’ returns of the Fund will be different from the returns of the Shares Class shares’ returns of the Fund as they have different expenses.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Updated performance information for the Fund is available and may be obtained on the Fund’s website at northerntrust.com/funds or by calling 800-595-9111.

CALENDAR YEAR TOTAL RETURN (CLASS K SHARES)*

* Year to date total return for the six months ended June 30, 2022 was (20.17)%. For the periods shown in the bar chart above, the highest quarterly return was 28.37% in the fourth quarter of 2020, and the lowest quarterly return was (29.37)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2021)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown only for Class K shares. After-tax returns for other classes will vary.

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SMALL CAP CORE FUND

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the Small Cap Core Fund. Robert H. Bergson, CFA, Senior Vice President of NTI, has been a manager of the Fund since February 2010 and Michael R. Hunstad, PhD, Senior Vice President of NTI has been a manager of the Fund since July 31, 2020. The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

PURCHASE AND SALE OF FUND SHARES

You may purchase Class I shares of the Fund only through an authorized intermediary. There is no minimum initial or subsequent investment amounts for Class I shares imposed by the Fund.

You may purchase Class K shares of the Fund by opening an account directly with Northern Funds (the “Trust”) with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 for Class K shares (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums. You may also purchase Class K shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary.

If you purchase, sell (redeem) or exchange Class K or Class I shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

TAX INFORMATION

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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U.S. QUALITY ESG FUND

INVESTMENT OBJECTIVE

The Fund seeks to provide long-term capital appreciation. Any income received is incidental to this objective.

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell Class I shares or Class K shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Class I or Class K shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in Class K shares and Class I shares of the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your Class K shares or Class I shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year end, the Fund’s portfolio turnover rate was 29.11% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

In seeking long-term capital appreciation, the Fund will invest, under normal circumstances, at least 80% of its net assets (plus borrowings for investment purposes) in equity securities of large and mid-capitalization U.S. companies that NTI believes have favorable environmental, social and governance (“ESG”) characteristics under a third-party vendor’s rating methodology. For purposes of this definition, U.S. companies with a market capitalization within the range of the Russell 1000^® Index will be considered large or mid-capitalization U.S. companies.

Using a quantitative, factor based approach, the Fund intends to invest in companies that: (i) meet certain criteria for ESG factors as provided by a third-party research vendor; (ii) exhibit strong business fundamentals, solid management and reliable cash flows; and (iii) are located, headquartered in, incorporated in or otherwise organized in the United States. The Fund expects its investments to be allocated among companies that are diversified in terms of industries and capitalization ranges.

The Fund is managed according to a quantitative model developed by NTI. To define an investable universe, NTI excludes securities of companies involved in ESG controversies under the United Nations Global Compact Principles. NTI also removes companies that, based on its evaluation of ESG data, appear to do a poor job of managing their ESG risks and opportunities relative to their peers as well as those with material involvement in controversial business practices, e.g., tobacco, civilian firearms, thermal coal, and both controversial and conventional weapons. NTI may modify this list of excluded companies at any time, without shareholder approval or notice.

NTI engages a third-party research vendor to provide ESG data for U.S. companies. The third-party vendor identifies ESG areas

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U.S. QUALITY ESG FUND

of risk and opportunity, evaluates exposure and management, and ranks and rates companies against their industry peers. The Fund’s ESG criteria is applied to all equity securities that are included in the Russell 1000^® Index, except that the Fund may at times hold securities that are subject to, or may hold securities as a result of, certain corporate actions, which securities may not be evaluated for ESG criteria.

After defining the investable universe, NTI evaluates the quality of the remaining securities and removes those securities that do not meet the proprietary quality methodology. NTI’s quality methodology rates and ranks securities based on three categories of financial signals (profitability, management efficiency, and cash generation). Those securities remaining from the investable universe are also rated and ranked based on NTI’s evaluation of their ESG characteristics.

The Fund is constructed based on an optimization methodology designed to take active exposure by overweighting and underweighting securities based on their ESG and relative financial quality rankings. NTI also performs a risk management analysis in which NTI seeks to measure and manage risk exposures at the security, sector and portfolio levels through portfolio diversification. NTI makes final purchase decisions based on the quantitative model described above and on the desired level of diversification. The Fund will normally sell a security that NTI believes is no longer attractive based upon the evaluation criteria described above. Further, in making purchase and sell decisions, NTI seeks to create a portfolio comprised of companies with a lower aggregate carbon footprint than the aggregate carbon footprint of the companies in the Russell 1000 Index, which includes consideration of a company’s emissions and carbon reserves as well as a company’s risk and opportunity alignment with a transition to a low carbon economy.

The Fund may use derivatives such as stock index futures contracts to equitize cash and enhance portfolio liquidity. ESG criteria are not applied to the Fund’s investments in derivatives.

From time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular sectors. As of March 31, 2022, the Fund focused its investments in the information technology sector.

Frank Russell Company does not endorse any of the securities in the Russell 1000 Index. It is not a sponsor of the Fund and is not affiliated with the Fund in any way.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets. Market risk includes the risk that a particular style of investing, such as growth or value, may underperform the market generally.

ESG INVESTING RISK is the risk stemming from the ESG factors that the Fund applies in selecting securities. The use of ESG factors in securities selection may affect the Fund’s exposure to certain companies or industries and cause the Fund to forego certain investment opportunities. The Fund’s performance results may be lower than other funds that do not use ESG factors, scores, or screens in their securities selection process, or use a different ESG methodology. Information used by the Fund to evaluate ESG factors, including data provided by the Fund’s third-party vendor, may not be readily available, complete or accurate, which could negatively impact the Fund’s ability to accurately determine companies’ ESG ratings, which in turn could negatively impact the Fund’s performance. Currently, there is a lack of common industry standards relating to the development and application of ESG criteria which may make it difficult to compare the Fund’s principal investment strategies with the investment strategies of other funds that apply certain ESG criteria or that use a different third-party vendor for ESG data. The Fund’s assessment of a company, based on the company’s level of involvement in a particular industry or ESG controversy or the company’s ESG ranking or rating, may differ from that of other funds or an investor. Information used by the Fund to evaluate ESG factors may vary across providers and issuers as ESG is not a uniformly defined characteristic. ESG standards differ by region and

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U.S. QUALITY ESG FUND

industry, and a company’s ESG practices or data providers’ assessment of a company’s ESG practices may change over time. As a result, the companies in which the Fund invests may not reflect the beliefs and values of any particular investor and may not be deemed to exhibit positive or favorable ESG characteristics if different metrics were used to evaluate them. Regulatory changes or interpretations regarding the definitions and/or use of ESG criteria could have a material adverse effect on the Fund’s ability to invest in accordance with its investment policies and/or achieve its investment objective.

MID CAP STOCK RISK is the risk that stocks of mid-sized companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Mid-sized companies may have limited product lines or financial resources, and may be dependent upon a particular niche of the market.

INVESTMENT STYLE RISK is the risk that different investment styles (e.g., “growth”, “value” or “quantitative”) tend to shift in and out of favor, depending on market and economic conditions as well as investor sentiment. The Fund may outperform or underperform other funds that invest in similar asset classes but employ a different investment style. The Fund may also employ a combination of styles that impacts its risk characteristics.

MANAGEMENT RISK is the risk that a strategy used by the Fund’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.

SECTOR RISK is the risk that companies in similar businesses may be similarly affected by particular economic or market events, which may, in certain circumstances, cause the value of securities of all companies in a particular sector of the market to decrease.

DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing: (A) changes in the performance of the Fund from year to year and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index.

The returns shown for periods ended prior to July 31, 2020 for the Class K shares and August 24, 2020 for the Class I shares are those of the Shares Class shares of the Fund at net asset value. Effective July 31, 2020, the Shares Class shares of the Fund were converted into new Class K shares and Class I shares of the Fund. Class K shares commenced operations on July 31, 2020 and Class I shares commenced operations on August 24, 2020. Class K and Class I shares’ returns of the Fund will be different from the returns of the Shares Class shares’ returns of the Fund as they have different expenses.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

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U.S. QUALITY ESG FUND

Updated performance information for the Fund is available and may be obtained on the Fund’s website at northerntrust.com/funds or by calling 800-595-9111.

CALENDAR YEAR TOTAL RETURN (CLASS K SHARES)*

* Year to date total return for the six months ended June 30, 2022 was (20.42)%. For the periods shown in the bar chart above, the highest quarterly return was 22.19% in the second quarter of 2020, and the lowest quarterly return was (19.11)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2021)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown only for Class K shares. After-tax returns for other classes will vary.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the U.S. Quality ESG Fund. Jeffrey D. Sampson, CFA and Peter M. Zymali, CFP^®, each a Senior Vice President of NTI, have been managers of the Fund since inception. The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

PURCHASE AND SALE OF FUND SHARES

You may purchase Class I shares of the Fund only through an authorized intermediary. There is no minimum initial or subsequent investment amounts for Class I shares imposed by the Fund.

You may purchase Class K shares of the Fund by opening an account directly with Northern Funds (the “Trust”) with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 for Class K shares (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums. You may also purchase Class K shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary.

If you purchase, sell (redeem) or exchange Class K or Class I shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

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U.S. QUALITY ESG FUND

TAX INFORMATION

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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EMERGING MARKETS EQUITY INDEX FUND

INVESTMENT OBJECTIVE

The Fund seeks to provide investment results approximating the overall performance of the MSCI Emerging Markets^® Index (the “Index”).

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares Class shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 20.35% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

Under normal circumstances, the Fund will invest substantially all (and at least 80%) of its net assets in equity securities, in weightings that approximate the relative composition of the securities included in the Index, in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”), and Global Depositary Receipts (“GDRs”) representing such securities, and in MSCI Emerging Markets Index futures approved by the Commodity Futures Trading Commission. The Fund’s common stock investments also include China A-shares (shares of companies based in mainland China that trade on the Shanghai Stock Exchange and the Shenzhen Stock Exchange).

The Index captures large and mid-cap representation across 24 Emerging Markets countries, as determined by the index provider, and covers approximately 85% of the free float-adjusted market capitalization in each country as of May 31, 2022. As of May 31, 2022, the Index was comprised of 1,393 constituents with market capitalizations ranging from $96.7 million to $457.3 billion. It is rebalanced quarterly. The Fund generally rebalances its portfolio in accordance with the Index.

NTI uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. NTI will buy and sell securities in response to changes in the Index as well as in response to subscriptions and redemptions.

The Fund generally invests in substantially all of the securities in the Index in approximately the same proportion as the Index (i.e., replication). In certain circumstances, however, the Fund may not hold every security in the Index or in the same proportion as the Index, such as to improve tax efficiency or when it may not be practicable to fully implement a replication

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EMERGING MARKETS EQUITY INDEX FUND

strategy. Rather, it will use an optimization strategy to seek to construct a portfolio that minimizes tracking error versus the Index while managing transaction costs and realized capital gains and losses.

The Fund intends to be diversified in approximately the same proportion as the Index is diversified. The Fund may become “non-diversified,” as defined in the Investment Company Act of 1940 (the “1940 Act”), solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the Index. A “non-diversified” fund can invest a greater percentage of its assets in a small group of issuers or in any one issuer than a diversified fund can. Shareholder approval will not be sought if the Fund becomes non-diversified due solely to a change in the relative market capitalization or index weighting of one or more constituents of the Index.

In seeking to track the performance of the Index, from time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular sectors, countries or geographic regions. As of March 31, 2022, the Fund focused its investments in China, Taiwan, and in the financial and information technology sectors.

NTI expects that, under normal circumstances, the quarterly performance of the Fund, before fees and expenses, will track the performance of the Index within a 0.95 correlation coefficient.

The Index is created and sponsored by Morgan Stanley Capital International, Inc. (“MSCI”), as the index provider. MSCI determines the composition and relative weightings of the securities in the Index and publishes information regarding the market value of the Index. MSCI does not endorse any of the securities in the Index. It is not a sponsor of the Emerging Markets Equity Index Fund and is not affiliated with the Fund in any way.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets.

EMERGING MARKETS RISK is the risk that emerging markets are generally subject to greater market volatility, political, social and economic instability, uncertain trading markets and more governmental limitations on foreign investments than more developed markets. In addition, companies operating in emerging markets may be subject to lower trading volumes and greater price volatility than companies in more developed markets. Emerging market economies may be based on only a few industries, may be highly vulnerable to changes in local and global trade conditions, and may suffer from extreme and volatile debt burdens or inflation rates. Companies in emerging market countries generally may be subject to less stringent regulatory, disclosure, financial reporting, accounting, auditing and recordkeeping standards than companies in more developed countries. As a result, information, including financial information, about such companies may be less available and reliable, which can impede the Fund’s ability to evaluate such companies. Securities law and the enforcement of systems of taxation in many emerging market countries may change quickly and unpredictably, and the ability to bring and enforce actions (including bankruptcy, confiscatory taxation, expropriation, nationalization of a company’s assets, restrictions on foreign ownership of local companies, restrictions on withdrawing assets from the country, protectionist measures and practices such as share blocking), or to obtain information needed to pursue or enforce such actions, may be limited. Investments in emerging market securities may be subject to additional transaction costs, delays in settlement procedures, unexpected market closures, and lack of timely information.

FOREIGN SECURITIES RISK is the risk that investing in foreign (non-U.S.) securities may result in the Fund experiencing more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies, due to less liquid markets and adverse economic, political, diplomatic, financial,

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EMERGING MARKETS EQUITY INDEX FUND

and regulatory factors. Foreign governments may impose limitations on foreigners’ ownership of interests in local issuers, restrictions on the ability to repatriate assets, and may also impose taxes. Any of these events could cause the value of the Fund’s investments to decline. Foreign banks, agents and securities depositories that hold the Fund’s foreign assets may be subject to little or no regulatory oversight over, or independent evaluation, of their operations. Additional costs associated with investments in foreign securities may include higher custodial fees than those applicable to domestic custodial arrangements and transaction costs of foreign currency conversions. Unless the Fund has hedged its foreign currency exposure, foreign securities risk also involves the risk of negative foreign currency rate fluctuations, which may cause the value of securities denominated in such foreign currency (or other instruments through which the Fund has exposure to foreign currencies) to decline in value. Currency exchange rates may fluctuate significantly over short periods of time. Currency hedging strategies, if used, are not always successful. For instance, forward foreign currency exchange contracts, if used by the Fund, could reduce performance if there are unanticipated changes in currency exchange rates.

GEOGRAPHIC RISK is the risk that if the Fund invests a significant portion of its total assets in certain issuers within the same country or geographic region, an adverse economic, business or political development affecting that country or region may affect the value of the Fund’s investments more, and the Fund’s investments may be more volatile, than if its investments were not so concentrated in such country or region.

DEPOSITARY RECEIPTS RISK Foreign securities may trade in the form of depositary receipts. In addition to investment risks associated with the underlying issuer, depositary receipts may expose the Fund to additional risks associated with non-uniform terms that apply to depositary receipt programs, including credit exposure to the depository bank and to the sponsors and other parties with whom the depository bank establishes the programs, currency, political, economic, market risks and the risks of an illiquid market for depositary receipts. Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. Depositary receipts may not track the price of the underlying foreign securities on which they are based, may have limited voting rights, and may have a distribution subject to a fee charged by the depository. As a result, equity shares of the underlying issuer may trade at a discount or premium to the market price of the depositary receipts.

TRACKING RISK is the risk that the Fund’s performance may vary from the performance of the index it tracks as a result of share purchases and redemptions, transaction costs, expenses and other factors.

SECTOR RISK is the risk that companies in similar businesses may be similarly affected by particular economic or market

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EMERGING MARKETS EQUITY INDEX FUND

events, which may, in certain circumstances, cause the value of securities of all companies in a particular sector of the market to decrease.

MID CAP STOCK RISK is the risk that stocks of mid-sized companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Mid-sized companies may have limited product lines or financial resources, and may be dependent upon a particular niche of the market.

INDEX RISK is the risk that that the Fund would not necessarily buy or sell a security unless that security is added or removed, respectively, from the Index, even if that security generally is underperforming, because unlike many investment companies, the Fund does not utilize an investing strategy that seeks returns in excess of the Index. Additionally, the Fund rebalances its portfolio in accordance with the Index, and, therefore, any changes to the Index’s rebalance schedule will result in corresponding changes to the Fund’s rebalance schedule.

DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

VALUATION RISK is the risk that the sale price the Fund could receive for a portfolio security may differ from the Fund’s valuation of the security, particularly for securities that trade in low volume or volatile markets or that are valued using a fair value methodology. Fair valuation of the Fund’s investments involves subjective judgment. In addition, the value of the securities in the Fund’s portfolio may change on days when shareholders will not be able to purchase or sell the Fund’s shares.

NON-DIVERSIFICATION RISK Under the 1940 Act, a fund designated as “diversified” must limit its holdings such that the securities of issuers which individually represent more than 5% of its total assets must in the aggregate represent less than 25% of its total assets. The Fund is “diversified” for purposes of the 1940 Act. However, in seeking to track its Index, the Fund may become “non-diversified,” as defined in the 1940 Act, solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the Index. A non-diversified fund can invest a greater portion of its assets in the obligations or securities of a small portion of its assets in the obligations or securities of a small number of issuers or any single issuer than a diversified fund can. In such circumstances, a change in the value of one or a few issuers’ securities will therefore affect the value of the Fund more than if it was a diversified fund.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

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EMERGING MARKETS EQUITY INDEX FUND

Updated performance information for the Fund is available and may be obtained on the Fund’s website at northerntrust.com/funds or by calling 800-595-9111.

CALENDAR YEAR TOTAL RETURN*

* Year to date total return for the six months ended June 30, 2022 was (17.35)%. For the periods shown in the bar chart above, the highest quarterly return was 19.07% in the fourth quarter of 2020, and the lowest quarterly return was (24.06)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2021)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds. Under certain circumstances, the addition of the tax benefits from capital losses resulting from redemptions may cause the Returns after taxes on distributions and sale of Fund shares to be greater than the Returns after taxes on distributions or even the Returns before taxes.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the Emerging Markets Equity Index Fund. Robert D. Anstine, Vice President of NTI and Brent D. Reeder, Senior Vice President of NTI, have been managers of the Fund since July 2019. The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

PURCHASE AND SALE OF FUND SHARES

You may purchase Shares Class shares of the Fund by opening an account directly with Northern Funds (the “Trust”) with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums. You may also purchase Shares Class shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary.

If you purchase, sell (redeem) or exchange Shares Class shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

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EMERGING MARKETS EQUITY INDEX FUND

TAX INFORMATION

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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GLOBAL REAL ESTATE INDEX FUND

INVESTMENT OBJECTIVE

The Fund seeks to provide investment results approximating the overall performance of the securities included in the MSCI^® ACWI^® IMI Core Real Estate Index (the “Index”).

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares Class shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 5.75% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

Under normal circumstances, the Fund will invest substantially all (and at least 80%) of its net assets in equity securities included in the Index, in weightings that approximate the relative composition of the securities contained in the Index, and in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”), and Global Depositary Receipts (“GDRs”) representing such securities. The Index is a free float-adjusted, market capitalization index that consists of large, mid and small-cap stocks engaged in the ownership, development and management of specific core property type real estate. The Index excludes companies, such as real estate services and real estate financing companies that do not own properties. The Fund will concentrate its investments (i.e., invest at least 25% or more of its total assets) in issuers principally engaged in real estate activities.

The Index is a free float-adjusted market capitalization index that consists of large, mid and small-cap stocks across 23 Developed Markets (DM) and 24 Emerging Markets (EM) countries engaged in the ownership, development and management of specific core property type real estate, as determined by the index provider. As of May 31, 2022, the Index was comprised of 698 constituents with market capitalizations ranging from $18.4 million to $116.6 billion. The Index is rebalanced quarterly. The Fund generally rebalances its portfolio in accordance with the Index.

NTI uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. NTI will buy and sell securities in response to changes in the Index as well as in response to subscriptions and redemptions. The Fund generally invests in substantially all of the securities in the Index in approximately the same proportions as the Index (i.e., replication). In certain

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GLOBAL REAL ESTATE INDEX FUND

circumstances, however, the Fund may not hold every security in the Index or in the same proportion as the Index, such as to improve tax efficiency or when it may not be practicable to fully implement a replication strategy. Rather, it will use an optimization strategy to seek to construct a portfolio that minimizes tracking error versus the Index while managing transaction costs and realized capital gains and losses.

The Fund intends to be diversified in approximately the same proportion as the Index is diversified. The Fund may become “non-diversified,” as defined in the Investment Company Act of 1940 (the “1940 Act”), solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the Index. A “non-diversified” fund can invest a greater percentage of its assets in a small group of issuers or in any one issuer than a diversified fund can. Shareholder approval will not be sought if the Fund becomes non-diversified due solely to a change in the relative market capitalization or index weighting of one or more constituents of the Index.

In seeking to track the performance of the Index, from time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular countries or geographic regions.

NTI expects that, under normal circumstances, the quarterly performance of the Fund, before fees and expenses, will track the performance of the Index within a 0.95 correlation coefficient.

The Index is created and sponsored by Morgan Stanley Capital International, Inc. (“MSCI”), as the index provider. MSCI determines the composition and relative weightings of the securities in the Index and publishes information regarding the market value of the Index. MSCI does not endorse any of the securities in the Index. It is not a sponsor of the Global Real Estate Index Fund and is not affiliated with the Fund in any way.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equity markets, market disruptions caused by local or regional events such as war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide due to increasingly interconnected global economies and financial markets.

REAL ESTATE SECURITIES CONCENTRATION RISK is the risk that investments in securities of real estate companies will make the Fund more susceptible to risks associated with the ownership of real estate and with the real estate industry in general. Real estate companies may have lower trading volumes and may be subject to more abrupt or erratic price movements than the overall securities markets. The value of real estate securities may underperform other sectors of the economy or broader equity markets. Because the Fund concentrates its investments in the real estate industry, it will be subject to greater risk of loss than if it were diversified across different industries.

REIT RISK is the risk that the Fund’s investments will be affected by factors affecting REITs and the real estate sector generally. Investing in REITs involves certain unique risks in addition to those risks associated with investing in the real estate industry in general. These risks include possible declines in the value of real estate, possible lack of mortgage funds and unexpected vacancies of properties. REITs that invest in real estate mortgages are also subject to prepayment risks. REITs whose underlying properties are concentrated in a particular industry or geographic region are also subject to risks affecting such industries and regions. REITs are also subject to heavy cash flow dependency, defaults by borrowers, self-liquidation, interest rate risks (especially mortgage REITs) and liquidity risks. REITs may have limited financial resources, may trade less frequently and in lower volume, engage in dilutive offerings or become more volatile than other securities. By investing in REITs through the Fund, a shareholder will bear expenses of the REITs in addition to expenses of the Fund. In addition, REITs could possibly fail to (i) qualify for favorable tax treatment under applicable tax law, or (ii) maintain their exemptions from registration under the 1940 Act.

FOREIGN SECURITIES RISK is the risk that investing in foreign (non-U.S.) securities may result in the Fund experiencing more

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rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies, due to less liquid markets and adverse economic, political, diplomatic, financial, and regulatory factors. Foreign governments may impose limitations on foreigners’ ownership of interests in local issuers, restrictions on the ability to repatriate assets, and may also impose taxes. Any of these events could cause the value of the Fund’s investments to decline. Foreign banks, agents and securities depositories that hold the Fund’s foreign assets may be subject to little or no regulatory oversight over, or independent evaluation, of their operations. Additional costs associated with investments in foreign securities may include higher custodial fees than those applicable to domestic custodial arrangements and transaction costs of foreign currency conversions. Unless the Fund has hedged its foreign currency exposure, foreign securities risk also involves the risk of negative foreign currency rate fluctuations, which may cause the value of securities denominated in such foreign currency (or other instruments through which the Fund has exposure to foreign currencies) to decline in value. Currency exchange rates may fluctuate significantly over short periods of time. Currency hedging strategies, if used, are not always successful. For instance, forward foreign currency exchange contracts, if used by the Fund, could reduce performance if there are unanticipated changes in currency exchange rates.

EMERGING MARKETS RISK is the risk that emerging markets are generally subject to greater market volatility, political, social and economic instability, uncertain trading markets and more governmental limitations on foreign investments than more developed markets. In addition, companies operating in emerging markets may be subject to lower trading volumes and greater price volatility than companies in more developed markets. Emerging market economies may be based on only a few industries, may be highly vulnerable to changes in local and global trade conditions, and may suffer from extreme and volatile debt burdens or inflation rates. Companies in emerging market countries generally may be subject to less stringent regulatory, disclosure, financial reporting, accounting, auditing and recordkeeping standards than companies in more developed countries. As a result, information, including financial information, about such companies may be less available and reliable, which can impede the Fund’s ability to evaluate such companies. Securities law and the enforcement of systems of taxation in many emerging market countries may change quickly and unpredictably, and the ability to bring and enforce actions (including bankruptcy, confiscatory taxation, expropriation, nationalization of a company’s assets, restrictions on foreign ownership of local companies, restrictions on withdrawing assets from the country, protectionist measures and practices such as share blocking), or to obtain information needed to pursue or enforce such actions, may be limited. Investments in emerging market securities may be subject to additional transaction costs, delays in settlement procedures, unexpected market closures, and lack of timely information.

TRACKING RISK is the risk that the Fund’s performance may vary from the performance of the index it tracks as a result of share purchases and redemptions, transaction costs, expenses and other factors.

GEOGRAPHIC RISK is the risk that if the Fund invests a significant portion of its total assets in certain issuers within the same country or geographic region, an adverse economic, business or political development affecting that country or region may affect the value of the Fund’s investments more, and the Fund’s investments may be more volatile, than if its investments were not so concentrated in such country or region.

DEPOSITARY RECEIPTS RISK Foreign securities may trade in the form of depositary receipts. In addition to investment risks associated with the underlying issuer, depositary receipts may expose the Fund to additional risks associated with non-uniform terms that apply to depositary receipt programs, including credit exposure to the depository bank and to the sponsors and other parties with whom the depository bank establishes the programs, currency, political, economic, market risks and the risks of an illiquid market for depositary receipts. Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. Depositary receipts may not track the price of the underlying foreign securities on which they are based, may have limited voting rights, and may have a distribution subject to a fee charged by the depository. As a result, equity shares of the underlying issuer may trade at a discount or premium to the market price of the depositary receipts.

SMALL AND MID CAP STOCK RISK is the risk that stocks of small and mid-sized companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies. Small and mid-sized companies may have limited product lines or financial resources, may be dependent upon a particular niche of the market, or may be dependent upon a small or inexperienced management group. The securities of small companies may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally, the smaller the company size, the greater the risk.

INDEX RISK is the risk that that the Fund would not necessarily buy or sell a security unless that security is added or removed, respectively, from the Index, even if that security generally is underperforming, because unlike many investment companies, the Fund does not utilize an investing strategy that seeks returns in excess of the Index. Additionally, the Fund rebalances its portfolio in accordance with the Index, and,

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therefore, any changes to the Index’s rebalance schedule will result in corresponding changes to the Fund’s rebalance schedule.

VALUATION RISK is the risk that the sale price the Fund could receive for a portfolio security may differ from the Fund’s valuation of the security, particularly for securities that trade in low volume or volatile markets or that are valued using a fair value methodology. In addition, the value of the securities in the Fund’s portfolio may change on days when shareholders will not be able to purchase or sell the Fund’s shares.

NON-DIVERSIFICATION RISK Under the 1940 Act, a fund designated as “diversified” must limit its holdings such that the securities of issuers which individually represent more than 5% of its total assets must in the aggregate represent less than 25% of its total assets. The Fund is “diversified” for purposes of the 1940 Act. However, in seeking to track its Index, the Fund may become “non-diversified,” as defined in the 1940 Act, solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the Index. A non-diversified fund can invest a greater portion of its assets in the obligations or securities of a small portion of its assets in the obligations or securities of a small number of issuers or any single issuer than a diversified fund can. In such circumstances, a change in the value of one or a few issuers’ securities will therefore affect the value of the Fund more than if it was a diversified fund.

As with any mutual fund, it is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

FUND PERFORMANCE

The bar chart and table that follow provide an indication of the risks of investing in the Fund by showing (A) changes in the performance of the Fund from year to year, and (B) how the average annual total returns of the Fund compare to those of a broad-based securities market index.

Effective July 31, 2018, the Fund changed its underlying index from the FTSE EPRA/NAREIT Global Index to the MSCI^® ACWI^® IMI Core Real Estate Index. Therefore, performance shown for periods prior to July 31, 2018 may have differed had the Fund sought to track its current Index. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

Updated performance information for the Fund is available and may be obtained on the Fund’s website at northerntrust.com/funds or by calling 800-595-9111.

CALENDAR YEAR TOTAL RETURN*

* Year to date total return for the six months ended June 30, 2022 was (19.76)%. For the periods shown in the bar chart above, the highest quarterly return was 14.73% in the first quarter of 2019, and the lowest quarterly return was (27.43)% in the first quarter of 2020.

AVERAGE ANNUAL TOTAL RETURN

(For the periods ended December 31, 2021)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

In calculating the federal income taxes due on redemptions, capital gains taxes resulting from redemptions are subtracted from the redemption proceeds and the tax benefits from capital losses resulting from the redemptions are added to the redemption proceeds.

MANAGEMENT

INVESTMENT ADVISER AND PORTFOLIO MANAGERS. NTI, an indirect subsidiary of Northern Trust Corporation, serves as the investment adviser of the Global Real Estate Index Fund. Volter Bagriy, Vice President of NTI, and Brent D. Reeder, Senior Vice President of NTI, have been managers of the Fund since July 2019. The Northern Trust Company, an affiliate of NTI, serves as transfer agent, custodian and sub-administrator to the Fund.

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PURCHASE AND SALE OF FUND SHARES

You may purchase Shares Class shares of the Fund by opening an account directly with Northern Funds (the “Trust”) with a minimum initial investment of $2,500 in the Fund ($500 for an IRA; $250 under the Automatic Investment Plan; and $500 for employees of Northern Trust and its affiliates). The minimum subsequent investment is $50 (except for reinvestments of distributions for which there is no minimum). The Fund reserves the right to waive these minimums. You may also purchase Shares Class shares of the Fund through an account at Northern Trust (or an affiliate) or an authorized intermediary.

If you purchase, sell (redeem) or exchange Shares Class shares through an authorized intermediary, you may be required to pay a commission and/or other forms of compensation to the intermediary. In addition, an authorized intermediary may impose different investment minimums than those set forth above. The Fund is not responsible for any investment minimums imposed by authorized intermediaries or for notifying shareholders of any changes to them.

On any business day, you may sell (redeem) or exchange shares through your account by contacting your Northern Trust account representative or authorized intermediary. If you purchase shares directly from the Trust, you may sell (redeem) or exchange your shares in one of the following ways:

TAX INFORMATION

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividend income, capital gains,

section 199A dividends or a combination of the four, unless you are investing through a tax-exempt or tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

PAYMENTS TO BROKERS-DEALERS AND OTHER FINANCIAL INTERMEDIARIES

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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INTERNATIONAL EQUITY INDEX FUND

INVESTMENT OBJECTIVE

The Fund seeks to provide investment results approximating the aggregate price and dividend performance of the securities included in the MSCI EAFE^® Index (the “Index”).

FEES AND EXPENSES OF THE FUND

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares Class shares, which are not reflected in the tables or the examples below.

EXAMPLE

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

PORTFOLIO TURNOVER. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual portfolio operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 20.76% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

Under normal circumstances, the Fund will invest substantially all (and at least 80%) of its net assets in the equity securities included in the Index, in weightings that approximate the relative composition of the securities contained in the Index, and in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”), and Global Depositary Receipts (“GDRs”) representing such securities and Index futures approved by the Commodity Futures Trading Commission.

The Index captures large and mid-cap representation across 21 Developed Markets countries around the world, as determined by the index provider, excluding the US and Canada, and covers approximately 85% of the free float-adjusted market capitalization in each country as of May 31, 2022. As of May 31, 2022, the Index was comprised of 826 constituents with market capitalizations ranging from $1.1 billion to $343.6 billion. It is rebalanced quarterly. The Fund generally rebalances its portfolio in accordance with the Index.

NTI uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. NTI will buy and sell securities in response to changes in the Index as well as in response to subscriptions and redemptions.

The Fund generally invests in substantially all of the securities in the Index in approximately the same proportions as the Index (i.e., replication). In certain circumstances, however, the Fund may not hold every security in the Index or in the same proportion as the Index, such as to improve tax efficiency or when it may not be practicable to fully implement a replication strategy. Rather, it will use an optimization strategy to seek to construct a portfolio that minimizes tracking error versus the Index while managing transaction costs and realized capital gains and losses.

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The Fund intends to be diversified in approximately the same proportion as the Index is diversified. The Fund may become “non-diversified,” as defined in the Investment Company Act of 1940 (the “1940 Act”), solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the Index. A “non-diversified” fund can invest a greater percentage of its assets in a small group of issuers or in any one issuer than a diversified fund can. Shareholder approval will not be sought if the Fund becomes non-diversified due solely to a change in the relative market capitalization or index weighting of one or more constituents of the Index.

The Fund may use derivatives such as stock index futures contracts to equitize cash and enhance portfolio liquidity.

In seeking to track the performance of the Index, from time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular sectors, countries or geographic regions. As of March 31, 2022, the Fund focused its investments in the financial and industrials sectors and in Japan, the United Kingdom and the European Union.

NTI expects that, under normal circumstances, the quarterly performance of the Fund, before fees and expenses, will track the performance of the Index within a 0.95 correlation coefficient.

The Index is created and sponsored by Morgan Stanley Capital International (“MSCI”), as the index provider. MSCI determines the composition and relative weightings of the securities in the Index and publishes information regarding the market value of the Index. MSCI does not endorse any of the securities in the Index. It is not a sponsor of the International Equity Index Fund and is not affiliated with the Fund in any way.

PRINCIPAL RISKS

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.