As filed with the Securities and Exchange Commission on April 29, 201527, 2018

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORMFORM 20-F

(Mark One)

OR

For the fiscal year ended December 31, 20142017

OR

For the transition period from    to    .

OR

Date of event requiring this shell company report    .

Commission file number000-53445

KB Financial Group Inc.

(Exact name of Registrant as specified in its charter)

KB Financial Group Inc.

(Translation of Registrant’s name into English)

The Republic of Korea

(Jurisdiction of incorporation or organization)

26,84, Namdaemoon-ro, Jung-gu,Gukjegeumyung-ro8-gil,Yeongdeungpo-gu, Seoul 100-703,07331, Korea

(Address of principal executive offices)

Kyu Sul ChoiPeter BongJoong Kwon

7F, Kookmin Bank 26,84, Namdaemoon-ro, Jung-gu,Gukjegeumyung-ro8-gil,Yeongdeungpo-gu, Seoul 100-703,07331, Korea

Telephone No.: +82-2-2073-2844+82-2-2073-2824

Facsimile No.: +82-2-2073-2848+82-2-2073-2848

(Name, telephone,e-mail and/or facsimile number and address of company contact person)

Securities registered or to be registered pursuant to Section 12(b) of the Act.

Securities registered or to be registered pursuant to Section 12(g) of the Act.

None

Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act.

None

Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report.

386,351,693399,037,583 shares of Common Stock, par value￦5,000 per share

Indicate by check mark if the registrant is awell-known seasoned issuer, as defined in Rule 405 of the Securities Act.  x☒ Yes  ¨☐ No

If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.  ¨☐ Yes  x☒ No

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.  x☒ Yes  ¨☐ No

Indicate by check mark whether the registrant has submitted electronically and posted on its Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of RegulationS-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).  ¨☐ Yes  ¨☐ No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, anon-accelerated filer or a non-accelerated filer.an emerging growth company. See definitionthe definitions of “large accelerated filer,” “accelerated filerfiler” and large accelerated filer”“emerging growth company” in Rule12b-2 of the Exchange Act. (Check one):Act:

x  ☒    Large accelerated filer             ¨☐     Accelerated filer             ☐¨    Non-accelerated Non-accelerated filer             ☐     Emerging growth company

If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act:  ☐ Yes  ☐ No

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:

If “Other” has been checked in response to the previous question, indicate by check mark which financial statement item the registrant has elected to follow.  ¨☐ Item 17  ¨☐ Item 18

If this is an annual report, indicate by check mark whether the registrant is a shell company (as defined in Rule12b-2 of the Exchange Act).  ¨☐ Yes  x☒ No

(APPLICABLE ONLY TO ISSUERS INVOLVED IN BANKRUPTCY PROCEEDINGS DURING THE PAST FIVE YEARS)

Indicate by check mark whether the registrant has filed all documents and reports required to be filed by Sections 12, 13 or 15(d) of the Securities Exchange Act of 1934 subsequent to the distribution of securities under a plan confirmed by a court.  ¨☐ Yes  ¨☐ No

* Not for trading, but only in connection with the registration of the American Depositary Shares.

TABLE OF CONTENTS

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PRESENTATION OF FINANCIAL AND OTHER INFORMATION

The financial statements included in this annual report are prepared in accordance with International Financial Reporting Standards, or IFRS, as issued by the International Accounting Standards Board, or IASB. As such, we make an explicit and unreserved statement of compliance with IFRS as issued by the IASB with respect to our consolidated financial statements as of January 1, 2013, December 31, 20132016 and 20142017 and for the years ended December 31, 2012, 20132015, 2016 and 20142017 included in this annual report. Unless indicated otherwise, the financial information in this annual report as of and for the years ended December 31, 2010, 2011, 2012, 2013, 2014, 2015, 2016 and 20142017 has been prepared in accordance with IFRS as issued by the IASB, which is not comparable to information prepared in accordance with generally accepted accounting principles in the United States, or U.S. GAAP.

In accordance with rule amendments adopted by the U.S. Securities and Exchange Commission which became effective on March 4, 2008, we are not required to provide a reconciliation to U.S. GAAP.

Unless expressly stated otherwise, all financial data included in this annual report are presented on a consolidated basis.

In this annual report:

Discrepancies between totals and the sums of the amounts contained in any table may be a result of rounding.

For your convenience, this annual report contains translations of Won amounts into U.S. dollars at the noon buying rate of the Federal Reserve Bank of New York for Won in effect on December 31, 2014,29, 2017, which was ￦1,090.9￦1,067.42 = US$1.00.

FORWARD-LOOKING STATEMENTS

The U.S. Securities and Exchange Commission encourages companies to discloseforward-looking information so that investors can better understand a company’s future prospects and make informed investment decisions. This annual report containsforward-looking statements.

Words and phrases such as “aim,” “anticipate,” “assume,” “believe,” “contemplate,” “continue,” “estimate,” “expect,” “future,” “goal,” “intend,” “may,” “objective,” “plan,” “positioned,” “predict,” “project,” “risk,” “seek to,” “shall,” “should,” “will likely result,” “will pursue,” “plan” and words and terms of similar substance used in connection with any discussion of future operating or financial performance or our expectations, plans, projections or business prospects identifyforward-looking statements. In particular, the statements under the headings “Item 3.D. Risk Factors,” “Item 5. Operating and Financial Review and Prospects” and “Item 4.B. Business Overview” regarding our financial condition and other future events or prospects areforward-looking statements. Allforward-looking statements are management’s present expectations of future events and are subject to a number of factors and uncertainties that could cause actual results to differ materially from those described in theforward-looking statements.

In addition to the risks related to our business discussed under “Item 3.D. Risk Factors,” other factors could cause actual results to differ materially from those described in theforward-looking statements. These factors include, but are not limited to:

By their nature, certain disclosures relating to these and other risks are only estimates and could be materially different from what actually occurs in the future. As a result, actual future gains, losses or impact on our income or results of operations could materially differ from those that have been estimated. For example, revenues could decrease, costs could increase, capital costs could increase, capital investment could be delayed and anticipated improvements in performance might not be fully realized.

In addition, other factors that could cause actual results to differ materially from those estimated by theforward-looking statements contained in this annual report could include, but are not limited to:

For further discussion of the factors that could cause actual results to differ, see the discussion under “Item 3.D. Risk Factors” contained in this annual report. We caution you not to place undue reliance on theforward-looking statements, which speak only as of the date of this annual report. Except as required by law, we are not under any obligation, and expressly disclaim any obligation, to update or alter anyforward-looking statements, whether as a result of new information, future events or otherwise.

All subsequentforward-looking statements attributable to us or any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this annual report.

Not applicable.

Not applicable.

The selected consolidated financial and operating data set forth below as of and for the years ended December 31, 2010, 2011, 2012, 2013, 2014, 2015, 2016 and 20142017 have been derived from our audited consolidated financial statements, which have been prepared in accordance with IFRS as issued by the IASB. Our consolidated financial statements as of and for the years ended December 31, 2010, 2011, 2012, 2013, 2014, 2015, 2016 and 20142017 have been audited by independent registered public accounting firm Samil PricewaterhouseCoopers.

You should read the following data together with the more detailed information contained in “Item 5. Operating and Financial Review and Prospects” and our consolidated financial statements included elsewhere in this annual report. Historical results do not necessarily predict future results.

Consolidated statements of comprehensive income data

Consolidated statements of financial position data