UNITED STATES SECURITIES AND EXCHANGE

COMMISSION

WASHINGTON, D.C. 20549

FORM 6-K

REPORT OF FOREIGN ISSUER PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of December, 2016

Commission file number: 1-10110

BANCO BILBAO VIZCAYA ARGENTARIA, S.A.

(Exact name of Registrant as specified in its charter)

BANK BILBAO VIZCAYA ARGENTARIA, S.A.

(Translation of Registrant’s name into English)

Calle Azul 4,

28050 Madrid

Spain

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):

Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

Condensed Interim

Consolidated Financial

Statements

Corresponding to the

Nine Months

ended September 30,

2016

Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS

NOTES TO THE ACCOMPANYING CONDENSED INTERIM CONSOLIDATED FINANCIAL STATEMENTS

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

Condensed Interim Consolidated balance sheets as of September 30, 2016 and December 31, 2015.

The accompanying Notes 1 to 10 are an integral part of the condensed interim consolidated balance sheet as of September 30, 2016.

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

Condensed Interim Consolidated income statements for the nine months ended September 30, 2016 and 2015

The accompanying Notes 1 to 10 are an integral part of the consolidated income statement corresponding to the nine months ended September 30, 2016.

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

Condensed Interim Consolidated statements of recognized income and expenses for the nine months ended September 30, 2016 and 2015

The accompanying Notes 1 to 10 are an integral part of the condensed interim consolidated statement of recognized income and expenses for the nine months ended September 30, 2016.

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

Condensed Interim Consolidated statements of changes in equity for the nine months ended September 30, 2016

The accompanying Notes 1 to 10 are an integral part of the condensed interim consolidated statement of changes in equity for the nine months ended September 30, 2016.

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

Condensed Interim Consolidated statements of changes in equity for the nine months ended September 30, 2015

(*)Presented solely and exclusively for comparison purposes (see Note 1).

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

Condensed Interim Consolidated statements of cash flows for the nine months ended September 30, 2016 and 2015

(*)Presented solely and exclusively for comparison purposes (see Note 1).

The accompanying Notes 1 to 10 are an integral part of the condensed interim consolidated statement of cash flows for the nine months ended September 30, 2016.

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

.

Notes to the condensed interim consolidated financial statements as of and for the period ended September 30, 2016

Introduction

Banco Bilbao Vizcaya Argentaria, S.A. (hereinafter “the Bank” or “BBVA”) is a private-law entity subject to the laws and regulations governing banking entities operating in Spain. It carries out its activity through branches and agencies across the country and abroad.

The Bylaws and other public information are available for inspection at the Bank’s registered address (Plaza San Nicolás, 4 Bilbao) as on its web site (www.bbva.com).

In addition to the transactions it carries out directly, the Bank heads a group of subsidiaries, joint venture and associated entities which perform a wide range of activities and which together with the Bank constitute the Banco Bilbao Vizcaya Argentaria Group (hereinafter, “the Group” or “the BBVA Group”). In addition to its own separate financial statements, the Bank is therefore required to prepare the Group’s consolidated financial statements.

The consolidated financial statements of the BBVA Group for the year ended December 31, 2015 were approved by the shareholders at the Annual General Meeting (“AGM”) on March 11, 2016.

Basis for the presentation of the condensed interim consolidated financial statements

The BBVA Group’s unaudited condensed interim consolidated financial statements (hereinafter, the “consolidated financial statements”) are presented in accordance with the International Accounting Standard 34 (“IAS 34”), on interim financial information for the preparation of financial statements for an interim period and have been presented to the Board of Directors at its meeting held on October 26,2016. According to IAS 34, the interim financial information is prepared solely with the purpose of updating the last prepared consolidated financial statements and interim consolidated financial statements, focusing on new activities, events and circumstances that occurred during the period without duplicating the information previously published in the last consolidated financial statements and interim consolidated financial statements. Therefore, the accompanying consolidated financial statements do not include all information required by a complete consolidated financial statements prepared in accordance with International Financial Reporting Standards, consequently for an appropriate understanding of the information included in them, they should be read together with the consolidated financial statements of the Group for the year ended December 31, 2015 and interim consolidated financial statements of the Group for the first semester 2016. The consolidated financial statements of the Group for the year ended December 31, 2015 and the interim consolidated financial statements of the Group for the first semester 2016, were presented in accordance with the International Financial Reporting Standards endorsed by the European Union (hereinafter, “EU-IFRS”) applicable as of December 31 2015 and June 30, 2016 respectively, considering the Bank of Spain Circular 4/2004, of 22 December (and as amended thereafter), and with any other legislation governing financial reporting applicable to the Group.

The accompanying consolidated financial statements were prepared applying the same principles of consolidation, accounting policies and valuation criteria, which as described in Note 2, are the same as those applied in the consolidated financial statements of the Group for the year ended December 31, 2015 and in the interim consolidated financial statements for the six months ended June 30, 2016, taking into account the standards and interpretations issued during the third quarter of 2016, so that they presented fairly the Group’s consolidated equity and financial position of the Group as of September 30, 2016, together with the consolidated results of its operations and the consolidated cash flows generated in the Group during the nine months ended September 30, 2016. These consolidated financial statements and explanatory notes were prepared on the basis of the accounting records kept by the Bank and each of the other entities in the Group, they include the adjustments and reclassifications required to harmonize the accounting policies and valuation criteria used by the Group.

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

All effective accounting standards and valuation criteria with a significant effect in the consolidated financial statements were applied in their preparation.

The amounts reflected in the accompanying consolidated financial statements are presented in millions of euros, unless it is more appropriate to use smaller units. Some items that appear without a total in these consolidated financial statements do so because of the size of the units used. Also, in presenting amounts in millions of euros, the accounting balances have been rounded up or down. It is therefore possible that the totals appearing in some tables are not the exact arithmetical sum of their component figures.

When determining the information to disclose about various items of the financial statements, the Group, in accordance with IAS 34, has taken into account their materiality in relation to the interim consolidated financial statements.

Comparative information

As of September 2016, the consolidated financial statements of BBVA Group are prepared in accordance with the presentation models required by Circular 5/2015 of the Comisión Nacional del Mercado de Valores. The aim is to adapt the content of the public financial information from the credit institutions and formats of the financial statements established mandatory by the European Union regulation for the credit institution.

The information included in the accompanying interim consolidated financial statements and the explanatory notes referring to December 31, 2015 and September 30, 2015 is presented exclusively for the purpose of comparison with the information for September 30, 2016.

In the first nine months ended September 30, 2016, the BBVA Group operating segments have not been significant changes with regard to the existing structure in 2015. The information related to operating segments as of December 31, 2015 and September 30, 2015 has been restated for comparability purposes, as required by IFRS 8 “Operating segments”.

Seasonal nature of income and expenses

The nature of the most significant operations carried out by the BBVA Group’s entities is mainly related to traditional activities carried out by financial institutions, which are not significantly affected by seasonal factors.

Responsibility for the information and for the estimates made

The information contained in the BBVA Group’s consolidated financial statements is the responsibility of the Group’s Directors.

Estimates have to be made at times when preparing these consolidated financial statements in order to calculate the recorded amount of some assets, liabilities, income, expenses and commitments. These estimates (see Notes 6, 7, 8 and 9) relate mainly to the following:

Although these estimates were made on the basis of the best information available as of September 30, 2016 on the events analyzed, future events may make it necessary to modify them (either up or down) over the coming years. This would be done prospectively in accordance with applicable standards, recognizing the effects of changes in the estimates in the corresponding consolidated income statement.

During the nine months ended September 30, 2016 there have been no significant changes to the assumptions made as of December 31, 2015, other than those indicated in these consolidated financial statements.

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

Related-party transactions

The information related to these transactions is presented in Note 53 of consolidated financial statements of the Group for the six months ended June 30, 2016.

As financial institutions, BBVA and other entities in the Group engage in transactions with related parties in the normal course of their business. All of these transactions are of little relevance and are carried out under normal market conditions.

The accounting policies and methods applied for the preparation of the accompanying consolidated financial statements are the same as those applied in the Interim Consolidated Financial Statements ended June 30, 2016.

Recent IFRS pronouncements

Changes introduced in 2016

The following modifications to the IFRS standards or their interpretations (hereinafter “IFRIC”) came into force after January 1, 2016. They have not had a significant impact on the BBVA Group’s consolidated financial statements corresponding to the period ended September 30, 2016.

Amended IFRS 11 – “Joint Arrangements”

The amendments made to IFRS 11 require the acquirer of an interest in a joint operation in which the activity constitutes a business to apply all of the principles on business combinations accounting in IFRS 3 and other IFRSs.

Amended IAS 16 – “Property, Plant and Equipment” and Amended IAS 38 – “Intangible Assets”

The amendments made to IAS 16 and IAS 38 exclude, as general rule, as depreciation method to be used, those methods based on revenue that is generated by an activity that includes the use of an asset, because the revenue generated by an activity that includes the use of an asset generally reflects factors other than the consumption of the economic benefits of the asset.

Amended IAS 27 – “Separate financial statements”

Changes to IAS 27 allow entities to use the equity method to account for investment in subsidiaries, joint ventures and associates, in their separate financial statements.

Annual improvements cycle to IFRSs 2012-2014

The annual improvements cycle to IFRSs 2012-2014 includes minor changes and clarifications to IFRS 5 – Non current assets held for sale and discontinued operations, IFRS 7 – Financial instruments: Information to disclose, IAS 19 – Employee benefits and IAS 34 – interim financial information.

Amended IAS 1 – Presentation of Financial Statements

The amendments made to IAS 1 further encourage companies to apply professional judgment in determining what information to disclose in their financial statements, in determining when line items are disaggregated and additional headings and subtotals included in the statement of financial position and the statement of profit or loss and other comprehensive income, and in determining where and in what order information is presented in the financial disclosures.

Amended IFRS 10 – “Consolidated Financial Statements”, Amended IFRS 12 – “Disclosure of interests in other entities” and Amended IAS 28 – “Investments in Associates and Joint Ventures”

The amendments to IFRS 10, IFRS 12 and IAS 28 introduce clarifications to the requirements when accounting for investment entities in three aspects:

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

Standards and interpretations issued but not yet effective as of September 30, 2016

New International Financial Reporting Standards together with their interpretations had been published at the date of preparation of the accompanying consolidated financial statements, but are not obligatory as of September 30, 2016. Although in some cases the IASB permits early adoption before they come into force, the BBVA Group has not done so as of this date, as it is still analyzing the effects that will result from them.

IFRS 9 – “Financial instruments”

The IASB has established January 1, 2018, as the mandatory application date, with the possibility of early adoption.

Amended IFRS 7 – “Financial instruments: Disclosures”

The IASB modified IFRS 7 in December 2011 to include new disclosures on financial instruments that entities will have to provide as soon as they apply IFRS 9 for the first time.

Amended IFRS 4 – “Applying IFRS 9 Financial Instruments with IFRS 4 Insurance Contracts”

The amendments introduce two approaches to address concerns that the financial statements of issuers of insurance contracts may be difficult to understand if IFRS 9 is applied before the forthcoming insurance contracts Standard:

IFRS 15 – “Revenue from contracts with customers” and “clarifications to IFRS 15”

This Standard will be applied to the accounting years starting on or after January 1, 2018, although early adoption is permitted.

Amended IFRS 10 – “Consolidated financial statements” and IAS 28 amended

These changes will be applicable to accounting periods beginning on the effective date, still to be determined, although early adoption is allowed.

IAS 12 – “Income Taxes. Recognition of Deferred Tax Assets for Unrealized Losses”

These modifications will be applied to the accounting periods beginning on or after January 1, 2017, although early application is permitted.

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

IFRS 16 – “Leases”

The standard will be applied to the accounting years starting on or after January 1, 2019, although early application is permitted if IFRS 15 is also applied.

IAS 7 – “Statement of Cash Flows. Disclosure Initiative”

These modifications will be applied to the accounting periods beginning on or after January 1, 2017, although early application is permitted.

IFRS 2 – “Classification and Measurement of Share-based Payment Transactions”

These modifications will be applied to the accounting periods beginning on or after January 1, 2018, although early application is permitted.

The BBVA Group is an international diversified financial group with a significant presence in retail banking, wholesale banking, asset management and private banking. The Group also operates in other sectors such as insurance, real estate, operational leasing, etc.

Appendices I and II of the Interim Consolidated Financial Statements for the first semester 2016, show relevant information as of June 30, 2016 related to the main subsidiaries and structured entities and joint ventures and associates accounted for using the equity method. Appendix III of the Interim Consolidated Financial Statements for the first semester 2016, show the main changes and notification of investments and divestments in the BBVA Group for the year ended June 30, 2016. Appendix IV of the Interim Consolidated Financial Statements for the first semester 2016, show fully consolidated subsidiaries with more than 10% owned by non-Group shareholders as of June 30, 2016.

The BBVA Group’s activities are mainly located in Spain, Mexico, South America, the United States and Turkey, with an active presence in other areas of Europe and Asia (see Note 5). There have been no significant variations in the Group during the third quarter of 2016.

Ongoing operations

Mergers

The BBVA Group, at its Board of Directors meeting held on March 31, 2016, adopted a resolution to begin a merger process of BBVA S.A. (absorbing company), Catalunya Banc, S.A., Banco Depositario BBVA, S.A. y Unoe Bank, S.A. This transaction is part of the corporate reorganization of its banking subsidiaries in Spain.

On September 9, 2016, after obtaining the authorization from the pertinent authorities, the deed of merger by absorption of Catalunya Banc, S.A. into BBVA was registered at the Bizkaia Commercial Registry.

These transactions have no impact in the consolidated financial statements both from the accounting and the solvency stand points.

On March 31, 2016, the Board of Directors approved the execution of the first of the share capital increases charged to voluntary reserves, as agreed by the AGM held on March 11, 2016 to implement the Dividend Option. As a result of this increase, the Bank’s share capital increased by €55,702,125.43 (113,677,807 shares at a €0.49 par value each). 82.13% of the right owners have opted to receive newly-issued BBVA ordinary shares. The other 17.87% of the right owners opted to sell the rights of free allocation assigned to them to BBVA, and as a result, BBVA acquired 1,137,500,965 rights for a total amount of €146,737,624.49. The price at which BBVA has acquired such rights of free allocation (in execution of said commitment) was €0.129 per right.

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Translation of the Interim Consolidated Financial Statements originally issued in Spanish and prepared in accordance with IAS 34, as
adopted by the European Union (See Note 1 and 10). In the event of a discrepancy, the Spanish-language version prevails.

The Board of Directors, at its meeting held on June 22, 2016, approved the distribution in cash of €0.08 (€0.0648 withholding tax) per BBVA share, as gross interim dividend against 2016 results. The dividend is expected to be paid on July 11, 2016. The total amount paid to the shareholder’s, after deducting the treasury shares held by the Group’s entities, amounted to €517million euros.

On September 28, 2016, the Board of Directors approved the execution of the first of the share capital increases charged to voluntary reserves, as agreed by the AGM held on March 11, 2016 to implement the Dividend Option. As a result of this increase, the Bank’s share capital increased by €42,266,085.33 (86,257,317 shares at a €0.49 par value each). 87.85% of the right owners have opted to receive newly-issued BBVA ordinary shares. The other 12.15% of the right owners opted to sell the rights of free allocation assigned to them to BBVA, and as a result, BBVA acquired 787,374,942 rights for a total amount of 62,989,995.36 €. The price at which BBVA has acquired such rights of free allocation (in execution of said commitment) was €0.08 per right.