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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, 2014

For the transition period from                      to                     

Commission file number 000-29599

PATRIOT NATIONAL BANCORP, INC.

(Exact name of registrant as specified in its charter)

(203) 324-7500

Registrant’s telephone number

Securities registered under Section 12(b) of the Exchange Act:

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

Common stock, $.01 par value 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

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 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 during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    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 registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendments to this Form 10-K.  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company.

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 common stock held by non-affiliates of the registrant was approximately $11.0 million based on the last sale price of the common stock as of June 30, 2014 (the last business day of the most recently completed second fiscal quarter).

There were 3,953,947 shares of our Common Stock issued and outstanding as of March 31, 2015.

DOCUMENTS INCORPORATED BY REFERENCE

None.

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EXPLANATORY NOTE

The annual report on Form 10-K of Patriot National Bancorp, Inc. (“Patriot”, “we”, “our”, “us”, or the “Company”) for the year ended December 31, 2014, was originally filed with the Securities and Exchange Commission (the “SEC”) on March 31, 2015, and this Amendment No. 1 is being filed solely to include responses to the items required by Part III. This Amendment No. 1 does not reflect events occurring after March 31, 2015, the date of the filing of our original Form 10-K, or modify or update those disclosures that may have been affected by subsequent events.

As required by Rule 12b-15 promulgated under the Securities and Exchange Act of 1934, our Chief Executive Officer and Chief Financial Officer are providing Rule 13a-14(a) certifications dated April 30, 2015 in connection with this Form 10-K/A and written statements pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 dated April 30, 2015.

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PART III

DIRECTORS, EXECUTIVE OFFICERS,

AND CORPORATE GOVERNANCE

Our executive officers and directors are as follows:

Background of Officers and Directors

Michael A. Carrazza

Mr. Carrazza has been Chairman of the Board of Directors of the Company since 2010. Through PNBK Sponsor, Mr. Carrazza manages PNBK Holdings, the Company’s largest shareholder. Mr. Carrazza is also CEO of Solaia Capital Advisors, an investment management company. In 2012, Mr. Carrazza led the spin-out of the Bank of Ireland’s U.S. Asset-Based Lending Group, now known as Siena Capital Finance, and serves as its Chairman. In 2004, he co-founded Bard Capital Group where he sponsored several transactions in the industrial sector. From 2001 until 2003, he was principal at The Glen Rock Group, a middle market investment firm, where he structured and financed the buyout of International Surface Preparation Group, Inc. (“ISPC”) from U.S. Filter/Vivendi. He subsequently worked at ISPC as Vice President in the office of the Chairman, managing the company’s financings, restructure and subsequent sale.

Kenneth T. Neilson

Mr. Neilson has been President and Chief Executive Officer since March 18, 2013 and has served as a director of Patriot since 2010. Mr. Neilson is the retired President, Chairman and CEO of Hudson United Bank and Hudson United Bancorp where he served for 23 years. After becoming President and CEO in 1989, Mr. Neilson led Hudson United Bancorp from a one state, 15 branch network with $500 million in assets, to a premiere franchise spanning four states with over 200 branch locations and an asset size of $9 billion by 2006 when it was sold to TD Banknorth. Mr. Neilson currently serves as a Board Member of Quinnipiac University.

Christina L. Maier

Ms. Maier has served as Executive Vice President and Chief Financial Officer of Patriot since October 1, 2013. Prior to joining the Bank, Ms. Maier served as Senior Vice President and Director, U.S. Accounting and Reporting at Brown Brothers Harriman, a multinational financial services firm she joined in October 2006. She was Senior Vice President and Controller of Provident New York Bancorp and served 15 years at Hudson United Bancorp, where she was First Senior Vice President, serving in capacities including Controller and Chief Accounting Officer.

Frederick Staudmyer

Mr. Staudmyer has served as Patriot’s Director of Human Resources since November 2014. He has also served as Corporate Secretary since January 2015. Mr. Staudmyer was most recently Assistant Dean for Career Management at Cornell University where he directed the Career Management Center. Prior to that he was the President, Chief Operating Officer and Managing Partner of a technology staffing company and also held positions at Manchester Partners, Ziff Publishing and Chase Manhattan Bank, all in a human resource capacity.

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Samuel S. Davis

Mr. Davis has served as Executive Vice President and Chief Credit Officer of Patriot since April 2013 and was the Bank’s Senior Lending Officer from September 2011 to April 2013. Prior to joining Patriot in November 2009, Mr. Davis was Senior Vice President of Lending at Connecticut Community Bank from January 2000 to November 2009.

Richard A. Muskus

Mr. Muskus has served as Executive Vice President and Chief Lending Officer of the Bank since February of 2014. Prior to joining the Bank, Mr. Muskus spent 13 years at Connecticut Community Bank serving as Senior Vice President of Commercial Lending and, from 2010, as President of its Greenwich Bank & Trust division.

Susan Neilson

Ms. Neilson has served as Executive Vice President and Chief Operating Officer of the Bank since January 2015. She had served as a consultant to the Bank since March of 2013. Prior to that Ms. Neilson served as Executive Vice President and Head of Retail Banking and Operations at Hudson United Bank, a $9 billion regional institution. She also led marketing, retail operations and deposit products for First Fidelity Bank and, earlier in her career, headed retail banking, technology and operations for Bank United, a $5 billion Texas-based thrift.

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Edward N. Constantino

Mr. Constantino has over 40 years of audit, advisory and tax experience working for two major accounting firms, Arthur Anderson LLP and KPMG LLP. Mr. Constantino retired from KPMG in late 2009, where he was an Audit Partner in charge of the Firm’s real estate and asset management businesses. Mr. Constantino is a member of the Board of Directors of ARC Property Trust and a member of the Audit Committee of the New York City Housing Authority. Mr. Constantino also serves as a consultant for the law firm of Skadden Arps. Mr. Constantino’s specific skills include auditing national and multinational organizations, internal control and compliance, financial reporting, regulatory reporting, risk management, asset valuation, accounting and finance and transaction structuring. He is a licensed CPA, a Member of the American Institute of Certified Public Accountants and a Member of the New York State Society of Public Accountants. He is currently a Member of the Board of Trustees and the Audit Committee Chairman of St. Francis College.

Raymond Smyth

Mr. Smyth served as our director from November 2008 until 2010 and since 2011. He is a retired partner in the accounting firm of Masotti & Masotti. In addition, he is a CPA and a financial expert.

Emile Van den Bol

Mr. Van den Bol is currently the Chief Executive Officer of Brooklawn Capital, LLC. Brooklawn Capital is an investment management company which advises and invests in real estate and securities. Mr. Van den Bol retired in 2010 as Managing Director of the Commercial Real Estate Group of Deutsche Bank Securities, Inc. Mr. Van den Bol joined Deutsche Bank in 2001 as Managing Director and held several executive positions in the Commercial Real Estate Group including Global Co-Head Structured Finance, Global Head Commercial Real Estate CDO Group and Member of the Global Commercial Real Estate Executive Committee. Mr. Van den Bol was from 2005 to 2009 a Governor of the Board of the Commercial Mortgage Securities Association. From 1996 to 2001 Mr. Van den Bol was employed by Lehman Brothers where he held a number of positions including Head of Esoteric Principal Finance Group and Co-Head of Lehman Brothers Franchise Conduit. Mr. Van den Bol was a member of Morgan Stanley’s Structured Finance Group from 1991 to 1996.

Michael J. Weinbaum

Mr. Weinbaum has been the Vice President of Real Estate Operations for United Capital Corp. for more than twenty years. Mr. Weinbaum has extensive experience in real estate operations and transactions. He is a member of the International Council of Shopping Centers and has been a member of United Capital’s Board of Directors since 2005. Mr. Weinbaum currently serves on the Finance Board and Board of Trustees for St. Mary’s Healthcare for Children.

There are no family relationships among our executive officers and directors, other than that between our CEO and President and our Executive Vice President and Chief Operating Officer, who are married. None of our executive officers or directors has, during the past five years:

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Section 16(a) Beneficial Ownership Reporting Compliance

Section 16(a) of the Securities Exchange Act of 1934 requires the Company’s officers, directors and persons who own more than ten percent of the issued and outstanding shares of Common Stock to file reports of beneficial ownership and changes in beneficial ownership with the SEC and to furnish copies of all Section 16(a) forms to the Company. No Form 3 or 4 filings are known to be late for any of the directors or beneficial owners of more than 10 percent of any class of equity securities of the Company in 2014. The following officers of the Company had one late filing each: Mr. Neilson, Mr. Muskus and Mr. Staudmyer. Mr. Davis and Ms. Maier each had two late filings.

Nominations to the Board of Directors

Stockholders may recommend individuals to the Nominating and Corporate Governance Committee of the Board of Directors for consideration as potential director candidates by submitting their names, together with appropriate biographical information and background materials, to the Nominating Committee, c/o Corporate Secretary, Patriot National Bancorp, Inc., 900 Bedford Street, Stamford, Connecticut 06901.

Code of Ethics

We have a Code of Ethics that governs all of our employees, including our CEO, CFO, principal accounting officer or persons performing similar functions. We will provide a copy of our Code of Ethics free of charge to any person upon written request to us at the following address: 900 Bedford Street, Stamford, Connecticut 06901; Attn: Chief Financial Officer.

Board of Directors

The Board of Directors currently consists of six members. Directors serve until their successors are duly elected or appointed. The Board of Directors has designated a Compensation Committee, Audit Committee, Nominating and Corporate Governance Committee and Executive Committee of the Board. Messrs. Constantino (chairman), and Van den Bol are members of the Compensation Committee; Messrs. Constantino (chairman), Smyth, and Van den Bol are members of the Audit Committee; Messrs. Van den Bol (chairman), Carrazza, Constantino and Weinbaum are members of the Nominating and Corporate Governance Committee; and Messrs Carrazza (chairman), Constantino, Neilson and Van den Bol are members of the Executive Committee of the Board.

Audit Committee Financial Expert

Our Board of Directors has determined that Edward N. Constantino and Raymond Smyth are the financial experts serving on our Audit Committee.

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EXECUTIVE COMPENSATION

Summary Compensation Table

The table below sets forth, for the last two fiscal years, the compensation earned by our Chief Executive Officer, Chief Financial Officer and the two other executive officers who received the highest annual compensation.

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401(k) Plan

The Bank maintains a tax-qualified 401(k) Plan under Section 401(a) of the Internal Revenue Code with a cash or deferred arrangement under Section 401(k) of the Internal Revenue Code. Employees become eligible to make salary reduction contributions to the 401(k) Plan and to receive any matching or discretionary contributions made to the 401(k) Plan by the Bank on the first day of the quarter coinciding with or next following the date that the employee has attained 21 years of age and completed at least 1,000 hours of service in a period of six to 12 consecutive calendar months.

Under the 401(k) Plan, participants may elect to have the Bank contribute a portion of their compensation each year, subject to certain limitations imposed by the Internal Revenue Code. The 401(k) Plan permits the Bank to make discretionary matching and additional discretionary contributions to the 401(k) Plan. Participants in the 401(k) Plan may direct the investment of their accounts in several types of investment funds.

Participants are always 100% vested in their elective deferrals, matching and discretionary matching contributions and related earnings under the 401(k) Plan. Participants are permitted to receive a distribution from the 401(k) Plan only in the form of a lump sum payment.

Patriot National Bancorp, Inc. 2012 Stock Plan

In 2011, Patriot adopted the Patriot National Bancorp, Inc. 2012 Stock Plan. The 2012 Plan is administered by the Compensation Committee of Patriot’s Board of Directors. Grants under the 2012 Plan may be made in the form of stock options, restricted stock and phantom stock units. The 2012 Plan authorizes 3,000,000 shares of Patriot’s common stock for issuance. Phantom stock units may be granted under the 2012 Plan up to 1,000,000 units.

Under the terms of the 2012 Plan, only Patriot employees and employees of its subsidiaries may receive stock options. The exercise price of the stock options shall be not less than the fair market value of the stock on the date of grant. The Compensation Committee shall determine the dates upon which the options may be exercisable, which shall not exceed 10 years from the date of grant. The options may be exercised on a cashless basis if approved by the Compensation Committee.

Under the original plan, only non-employee directors were eligible to receive grants of restricted stock. Those grants generally vest in quarterly installments over a four year period from the date of grant. In September 2013 an amendment to the Stock Plan was approved by Patriot’s stockholders. The Plan was amended to expand the persons eligible to receive grants of restricted stock under the 2012 Plan to include officers of the Company and its subsidiaries. The vesting of these grants generally occurs in annual installments over a five year period. The vesting of restricted stock awards and options may be accelerated in accordance with terms of the plan. The Compensation Committee shall make the terms and conditions applicable to the vesting of restricted stock awards and stock options.

Only Patriot’s employees and employees of its subsidiaries are eligible to receive phantom stock units under the 2012 Plan. The phantom stock units entitle the holder to receive upon exercise, in cash or shares of common stock, the appreciation in the value of the common stock from the date of grant. The Plan Committee shall determine the terms and conditions of each phantom stock unit award. Upon a change of control of Patriot, the grantee shall be required to redeem all of his or her phantom stock units. In the event of a sale of substantially all of Patriot’s assets, all outstanding phantom stock units will be redeemed

Under Patriot’s 2012 Stock Plan, 15,216 shares of restricted stock and 85,000 of stock options were awarded in 2012. 32,964 shares of restricted stock were awarded in 2013. During 2014, the Company issued 73,558 shares of restricted stock.

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Director Compensation

The following table details the compensation paid to or accrued for each of Patriot’s non-management directors in 2014:

Patriot’s directors who are also executive officers do not receive compensation for service on the board of directors or any of its committees. Non-employee directors of Patriot receive $750 for each board meeting in which they participate and fees ranging from $250 to $500 for each committee meeting in which they participate. In addition, non-employee directors who serve as the chair of a committee receive additional fees ranging from $2,000 to $6,000 per year.

Our directors are also reimbursed for reasonable and necessary out-of-pocket expenses incurred in connection with their service to us, including travel expenses.

Securities Authorized for Issuance under Equity Compensation Plans

The Company has 3,000,000 shares of common stock authorized for issuance under the 2012 Stock Plan, of which 2,881,745 shares of stock are available for issuance.

SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The table below provides certain information about beneficial ownership of common stock of the Company as of April 27, 2015 with respect to: (i) each person, or group of affiliated persons, who is known to the Company to own more than five percent (5%) of Company common stock; (ii) each of the Company’s directors; (iii) each of the Company’s executive officers; and (iv) all of the Company’s directors and executive officers as a group.

Except as otherwise noted, to the knowledge of the Company, all persons listed below have sole voting and dispositive power with respect to all shares of common stock they beneficially own, except to the extent authority is shared by spouses under applicable law. Applicable percentage ownership is based on 3,953,947 shares of common stock outstanding. In computing the number of shares of common stock beneficially owned by a person and applicable percentage ownership of that person, we deemed outstanding shares of common stock subject to options held by that person that are currently exercisable or exercisable within sixty (60) days of April 27, 2015. We did not deem these shares outstanding, however, for the purpose of computing the percentage ownership of any other person.

Unless otherwise indicated, the address of each shareholder is in care of Patriot National Bancorp, Inc., 900 Bedford Street, Stamford, CT 06901.

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Directors and Officers of Patriot

In the ordinary course of business, the Bank has made loans to officers and directors (including loans to members of their immediate families and loans to companies of which a director owns 10% or more). There were no loans to officers and directors outstanding as of December 31, 2014. In the opinion of management, all of such loans were made in the ordinary course of business of the Bank on substantially the same terms, including interest rates and collateral requirements, as those then prevailing for comparable transactions with persons not related to the lender. The Bank believes that at the time of origination these loans neither involved more than the normal risk of collectibility nor presented any other unfavorable features.

Information about transactions involving related persons is assessed by Patriot’s independent directors. Related persons include Patriot’s directors and executive officers as well as immediate family members of directors and officers. If the independent directors approve or ratify a material transaction involving a related person, then the transaction would be disclosed in accordance with the SEC rules. If the related person is a director, or a family member of a director, then that director would not participate in those discussions.

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Board Independence

We are subject to the listing standards of the SEC rules pertaining to director independence, and we believe that Messrs. Constantino, Smyth, Van den Bol and Weinbaum are “independent” directors as that term is defined by applicable listing standards of the Nasdaq stock market and SEC rules, including the rules relating to the independence standards of an audit committee and the non-employee definition of Rule 16b-3 promulgated under the Exchange Act.

The following table sets forth the principal accounting fees we paid to KPMG LLP, an independent registered public accounting firm, with respect to our fiscal years ended December 31, 2014 and 2013for: (i) services rendered for the audit of our annual financial statements and the review of our quarterly financial statements; (ii) services rendered that are reasonably related to the performance of the audit or review of our financial statements and that are not reported as audit fees; (iii) services rendered in connection with tax compliance, tax advice and tax planning; and (iv) all other services rendered.

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Audit Committee Pre-Approval Policies and Procedures

The Audit Committee has adopted a policy for pre-approval of audit and permitted non-audit services by the Company’s independent registered public accountants. The Audit Committee will consider annually and, if appropriate, approve the provision of audit services by its external auditor and consider and, if appropriate, pre-approve the provision of certain defined audit and non-audit services. The Audit Committee also will consider on a case-by-case basis and, if appropriate, approve specific engagements that are not otherwise pre-approved.

Any proposed engagement that does not fit within the definition of a pre-approved service may be presented to the Audit Committee for consideration at its next regular meeting or, if earlier consideration is required, to the Audit Committee or one or more of its members. The member or members to whom such authority is delegated shall report any specific approval of services at its next regular meeting. The Audit Committee will regularly review summary reports detailing all services being provided to the Company by its external auditor.

The Audit Committee approved the audit-related fees, tax fees and all other fees set forth above for the year ended December 31, 2014.

PART IV

(b) Index to Exhibits

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SIGNATURES

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

In accordance with the Exchange Act, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

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