UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-K/A

(Amendment No. 1)

(Mark One)

For the Fiscal Year Ended December 31, 2013

OR

For the transition period from                      to                     

Commission file number 814-00188

MEDALLION FINANCIAL CORP.

(Exact name of registrant as specified in its charter)

437 MADISON AVENUE, 38^th Floor, NEW YORK, NEW YORK 10022

(Address of principal executive offices) (Zip Code)

(212) 328-2100

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act: None

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

Common Stock, par value $0.01 per share

(Title of class)

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    YES  ¨    NO  x

Indicated by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act:    YES  ¨    NO  x

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.    YES  x    NO  ¨

Indicate by check mark whether the Registrant has submitted electronically and posted on its corporate web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or such shorter period that the Registrant was required to submit and post such files).    YES  ¨    NO  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein and will not be contained, to the best of the registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K  x

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer,” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (check one):

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act)    YES  ¨    NO  x

The aggregate market value of the voting common equity held by non-affiliates of the registrant, computed by reference to the last reported price at which the stock was sold on June 30, 2013 was $260,913,987.

The number of outstanding shares of registrant’s Common Stock, par value $0.01, as of June 19, 2014 was 25,162,453.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s Definitive Proxy Statement for its 2014 Annual Meeting of Shareholders are incorporated by reference into Part III of this Form 10-K.

EXPLANATORY NOTE

Medallion Financial Corp. (the “Company”) hereby amends its Annual Report on Form 10-K for the fiscal year ended December 31, 2013, as filed with the Securities and Exchange Commission on March 5, 2014 (the “Original Form 10-K”). The Company is filing this Amendment No. 1 on Form 10-K/A (this “Amendment”) solely to change an incorrect date contained in the last paragraph of the electronic version of WeiserMazars LLP’s Report of Independent Registered Public Accounting Firm (the “Report”) relating to the financial statements included in the Original Form 10-K from March 5, 2013 to March 5, 2014. The manually signed copy of the Report that was received by the Company from WeiserMazars LLP did not contain the aforementioned scrivener’s error.

This Amendment speaks as of the filing date of the Original Form 10-K, does not reflect events that have occurred after the filing date of the Original Form 10-K and does not amend, modify or update in any way disclosures made in the Original Form 10-K except as set forth in this explanatory note.

Report of Independent Registered Public Accounting Firm

To the Board of Directors and Shareholders of Medallion Financial Corp.

We have audited the accompanying consolidated balance sheets of Medallion Financial Corp. and subsidiaries (the “Company”), including the consolidated summary schedule of investments, as of December 31, 2013 and 2012, and the related consolidated statements of operations, changes in net assets, and cash flows for each of the three years in the three-year period ended December 31, 2013 and the selected financial ratios and other data (see note 13) for each of the five years in the five-year period ended December 31, 2013. We have also audited the consolidated schedules of investments in and advances to affiliates as of and for the years ended December 31, 2013 and 2012. These consolidated financial statements, selected financial ratios and other data, and schedules are the responsibility of the Company’s management. Our responsibility is to express an opinion on these consolidated financial statements, selected financial ratios and other data, and schedules based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements, selected financial ratios and other data, and schedules are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the consolidated financial statements. Our procedures included physical inspection or confirmation of securities owned as of December 31, 2013 and 2012. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall consolidated financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the consolidated financial statements and the selected financial ratios and other data referred to above present fairly, in all material respects, the consolidated financial position of the Company as of December 31, 2013 and 2012, and the consolidated results of their operations, changes in net assets, and cash flows for each of the three years in the three-year period ended December 31, 2013 and the selected financial ratios and other data for each of the five years in the five-year period ended December 31, 2013, in conformity with US generally accepted accounting principles. Also, in our opinion, the consolidated schedules of investments in and advances to affiliates, when considered in relation to the basic consolidated financial statements taken as a whole, present fairly, in all material respects, the information set forth therein.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the Company’s internal control over financial reporting as of December 31, 2013, based on the criteria established in Internal Control-Integrated Framework (1992) issued by the Committee of Sponsoring Organizations of the Treadway Commission (“COSO”), and our report dated March 5, 2014 expressed an unqualified opinion on the effectiveness of the Company’s internal control over financial reporting.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange of Act of 1934, registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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