UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K/A

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of November 2017

Commission File Number: 000-53445

KB Financial Group Inc.

(Translation of registrant’s name into English)

84, Namdaemoon-ro, Jung-gu, Seoul 04534, Korea

(Address of principal executive office)

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

Form 20-F  ☒             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):  ☐

Note: Regulation S-T Rule 101(b)(1) only permits the submission in paper of a Form 6-K if submitted solely to provide an attached annual report to security holders.

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):  ☐

Note: Regulation S-T Rule 101(b)(7) only permits the submission in paper of a Form 6-K if submitted to furnish a report or other document that the registrant foreign private issuer must furnish and make public under the laws of the jurisdiction in which the registrant is incorporated, domiciled or legally organized (the registrant’s “home country”), or under the rules of the home country exchange on which the registrant’s securities are traded, as long as the report or other document is not a press release, is not required to be and has not been distributed to the registrant’s security holders, and, if discussing a material event, has already been the subject of a Form 6-K submission or other Commission filing on EDGAR.

EXPLANATORY NOTE

This Report of Foreign Private Issuer on Form 6-K/A (this “Amended Report”) is furnished to amend the Report of Foreign Private Issuer furnished to the Securities and Exchange Commission on October 31, 2017 under the title “Notice regarding the Convocation of Extraordinary General Meeting of Shareholders” (the “Original Report”) solely to correct a date appearing therein. This Amended Report amends the Original Report to change the expiration date of the term of office for Mr. Yin Hur, our nominee for non-standing director, from the date of the 11th annual general meeting of shareholders, which is expected to be held in March 2019, to the date of the 12th annual general meeting of shareholders, which is expected to be held in March 2020, under “Agendum 2. Appointment of a non-standing director” of “Details of the Agenda for Extraordinary General Meeting of Shareholders” of the Original Report. No other change to the Original Report is made by this Amended Report.

The entirety of the Original Report, as amended by this Amended Report, is set forth below.

Notice regarding the Convocation of Extraordinary General Meeting of Shareholders

Meeting Description

Agenda

Details of the Agenda for Extraordinary General Meeting of Shareholders

Agendum 1. Appointment of an executive director

Nominee for Executive Director

Agendum 2. Appointment of a non-standing director

Nominee for Non-standing Director

Agendum 3. Appointment of a non-executive director (proposed by the Labor Union of Kookmin Bank and others)

Nominee for Non-executive Director

Agendum 4. Amendment of the Articles of Incorporation (proposed by the Labor Union of Kookmin Bank and others)

The following table sets forth a summary of the proposed amendments to the Articles of Incorporation:

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.