QuickLinks -- Click here to rapidly navigate through this document

As filed with the Securities and Exchange Commission on September 25, 2006

Registration No. 333-            



UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, DC 20549


Form S-1

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

Patriot National Bancorp, Inc.
(Exact name of registrant as specified in its charter)

Connecticut
(State or other jurisdiction
of incorporation or organization)
  6021
(Primary Standard Industrial
Classification Code Number)
  06-1559137
(I.R.S. Employer Identification Number)

900 Bedford Street
Stamford, Connecticut 06901
(203) 324-7500
(Address, including zip code, and telephone number, including area code, of registrant's principal executive offices)

Charles F. Howell
President
  Robert F. O'Connell
Senior Executive Vice President and
Chief Financial Officer

Patriot National Bancorp, Inc.
900 Bedford Street
Stamford, Connecticut 06901
(203) 324-7500
(Name, address, including zip code, and telephone number, including area code, of agent for service)


Copies to:

William W. Bouton III, Esq.
Kerry John Tomasevich, Esq.
Tyler Cooper & Alcorn, LLP
185 Asylum Avenue
City Place 35th Floor
Hartford, CT 06103-3488
(860) 725-6200
  Norman B. Antin, Esq.
Jeffrey D. Haas, Esq.
Patton Boggs LLP
2550 M Street, NW
Washington, DC 20037
(202) 457-6000

Approximate date of commencement of proposed sale to the public:
As soon as practicable after the effective date of this Registration Statement.

        If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933 check the following box: o

        If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration number of the earlier effective registration statement for the same offering. ý 333-136824

        If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration number of the earlier effective registration statement for the same offering. o

        If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration number of the earlier effective registration statement for the same offering. o


CALCULATION OF REGISTRATION FEE


Title of each class of
securities to be registered

  Amount to be
registered

  Proposed maximum Offering
price per share(1)

  Proposed maximum aggregate
offering price(1)

  Amount of
registration fee


Common Stock, $2.00 par value   235,000 shares(2)   $22.00   $5,170,000   $554

(1)
Estimated solely for the purpose of determining the registration fee and computed pursuant to Rule 457 based upon the public offering price of $22.00.

(2)
Includes a total of 15,000 shares that are subject to an over-allotment option granted to the underwriters.

        This Registration Statement shall become effective upon filing with the Commission in accordance with Rule 462(b) under the Securities Act of 1933.





EXPLANATORY NOTE AND
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

        This registration statement is being filed with respect to the registration of additional shares of common stock, $2.00 par value per share, of Patriot National Bancorp. Inc., a Connecticut corporation, for an offering pursuant to Rule 462(b) under the Securities Act of 1933, as amended. The contents of the registrant's earlier effective registration statement on Form S-1 (File No. 333-136824) are incorporated into this registration statement by reference. The form of prospectus contained in the earlier effective registration statement will reflect the aggregate amount of securities registered in this registration statement and the earlier effective registration statement.

        The required opinions and consents are listed on an Exhibit Index attached hereto and filed herewith.



SIGNATURES

        In accordance with the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements of filing on Form S-1 and authorized this Registration Statement to be signed on its behalf by the undersigned, in the City of Stamford, State of Connecticut, on September 25, 2006.

    PATRIOT NATIONAL BANCORP, INC.
(REGISTRANT)

 

 

By:

/s/  
ANGELO DE CARO      
Angelo De Caro
Chairman & Chief Executive Officer

        In accordance with the requirements of the Securities Act of 1933, this registration statement was signed by the following persons in the capacities and on the dates stated.

Signature
  Title
  Date

 

 

 

 

 
/s/  ANGELO DE CARO      
Angelo De Caro
  Chairman and Chief Executive Officer (Principal Executive Officer)   September 25, 2006

/s/  
CHARLES F. HOWELL      
Charles F. Howell

 

Vice Chairman and President

 

September 25, 2006

/s/  
ROBERT F. O'CONNELL      
Robert F. O'Connell

 

Senior Executive Vice President, Chief Financial Officer and Director (Principal Financial Officer)

 

September 25, 2006

/s/  
MICHAEL A. CAPODANNO *      
Michael A. Capodanno

 

Senior Vice President and Controller (Principal Accounting Officer)

 

September 25, 2006

/s/  
PHILIP W. WOLFORD *      
Philip W. Wolford

 

Chief Operating Officer and Director

 

September 25, 2006

/s/  
JOHN J. FERGUSON *      
John J. Ferguson

 

Director

 

September 25, 2006

/s/  
BRIAN A. FITZGERALD *      
Brian A. Fitzgerald

 

Director

 

September 25, 2006
         


/s/  
JOHN A. GEOGHEGAN *      
John A. Geoghegan

 

Director

 

September 25, 2006

/s/  
L. MORRIS GLUCKSMAN *      
L. Morris Glucksman

 

Director

 

September 25, 2006

/s/  
MICHAEL F. INTRIERI *      
Michael F. Intrieri

 

Director

 

September 25, 2006

*By:

 

/s/  
ROBERT F. O'CONNELL    

Robert F. O'Connell
Attorney-in-Fact

 

 

 

 


EXHIBIT INDEX

EXHIBIT NUMBER

  DESCRIPTION OF EXHIBIT

5

 

Opinion of Tyler, Cooper & Alcorn, LLP. Filed herewith.

23.1

 

Consent of McGladrey & Pullen, independent auditors. Filed herewith.

23.2

 

Consent of Tyler, Cooper & Alcorn, LLP. Included in Exhibit 5.

24.1*

 

Power of attorney.

*
Filed with the Company's Registration Statement on Form S-1 (Registration No. 333-136824).



QuickLinks

EXPLANATORY NOTE AND INCORPORATION OF CERTAIN INFORMATION BY REFERENCE
SIGNATURES
EXHIBIT INDEX