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As filed with the Securities and Exchange Commission on June 9, 2005            
        
                                                  Registration No. _____________

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                        UNDER THE SECURITIES ACT OF 1933

                            SI FINANCIAL GROUP, INC.
             (exact name of registrant as specified in its charter)

        United States                                   84-1655232
        -------------                                   ----------
(State or other jurisdiction of                (IRS Employer Identification No.)
incorporation or organization) 

                                 803 Main Street
                              Willimantic, CT 06226
                                (860) 423-4581 
              (Address, including zip code, and telephone number,
        including area code, of registrant's principal executive offices)

               SI Financial Group, Inc. 2005 Equity Incentive Plan
                            (Full Title of the Plan)
                    ---------------------------------------

                                                    Copies to:
Rheo A. Brouillard                                  Eric S. Kracov, Esq.
President and Chief Executive Officer               Victor Cangelosi, Esq.
SI Financial Group, Inc.                            Muldoon Murphy & Aguggia LLP
803 Main Street                                     5101 Wisconsin Avenue, N.W.
Willimantic, CT 06226                               Washington, D.C.  20016
(860) 423-4581                                      (202) 362-0840
(Name, address, including zip code, and telephone
number, including area code, of agent for service)



==================================================================================================
                                           Proposed         Proposed Maximum
Title of Securities      Amount        Maximum Offering    Aggregate Offering      Amount of
 to be Registered   to be Registered    Price Per Share(3)        Price          Registration Fee
--------------------------------------------------------------------------------------------------
                                                                       
   Common Stock
   $.01 par Value      615,623 (2)        $10.25              $6,310,136           $743
--------------------------------------------------------------------------------------------------
   Common Stock
   $.01 par Value      246,249 (4)        $10.25              $2,524,053           $298

===================================================================================================


(1) Together with an indeterminate number of additional shares which may be
    necessary to adjust the number of shares reserved for issuance pursuant to
    the SI Financial, Group, Inc. 2005 Equity Incentive Plan (the "Plan") as the
    result of a stock split, stock dividend or similar adjustment to the
    outstanding common stock of SI Financial Group, Inc. (the "Common Stock")
    pursuant to 17 C.F.R. ss.230.416(a).
(2) Represents the total number of shares currently reserved for issuance upon
    the exercise of stock options under the Plan.
(3) Estimated solely for the purpose of calculating the amount of the
    registration fee. Pursuant to Rule 457(c) under the Securities Act of 1933,
    as amended (the "Securities Act"), the price per share is estimated to be
    $10.25 based upon the average of the high and low price of the Common Stock,
    as reported on the Nasdaq National Market on June 7, 2005.
(4) Represents the total number of shares currently reserved for issuance as
    restricted stock awards under the Plan.

THIS REGISTRATION STATEMENT SHALL BECOME EFFECTIVE IMMEDIATELY UPON FILING IN
ACCORDANCE WITH SECTION 8(A) OF THE SECURITIES ACT OF 1933, AS AMENDED, (THE
"SECURITIES ACT") AND 17 C.F.R. SS.230.462.

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SI FINANCIAL GROUP, INC.

PART I   INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS

ITEMS 1 & 2. The documents containing the information for the SI Financial
Group, Inc. 2005 Equity Incentive Plan (the "Plan") specified by Part I of this
Registration Statement will be sent or given to the participants in the Plan as
specified by Rule 428(b)(1). Such documents need not be filed with the
Securities and Exchange Commission (the "SEC") either as a part of this
Registration Statement or as a prospectus or prospectus supplement pursuant to
Rule 424 in reliance on Rule 428. Such documents and the information
incorporated by reference pursuant to Item 3 of Part II of this Registration
Statement, taken together, constitute a prospectus for the Registration
Statement.

PART II  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE

      The following documents filed or to be filed by SI Financial Group, Inc.
(the "Registrant" or the "Corporation") with the SEC are incorporated by
reference in this Registration Statement:

      (a) The Registrant's Quarterly Report on the Form 10-Q for the quarter
ended March 31, 2005 (File No. 000-50801) filed with the SEC on May 13, 2005.

      (b) The Corporation's Annual Report on Form 10-K for the fiscal year ended
December 31, 2004, which includes the consolidated statements of income, changes
in stockholders' equity and cash flows for each of the three years in the period
ended December 31, 2004 filed with the SEC on March 29, 2005 (File No.
000-50801).

      (c) The description of the Registrant's common stock contained in the
Registrant's Form 8- A (File No. 000-50801), as filed with the SEC on June 15,
2004, pursuant to Section 12(g) of the Securities Exchange Act of 1934 (the
"Exchange Act"), and rule 12b-15 promulgated thereunder.

      (d) All documents filed by the Registrant pursuant to Sections 13(a) and
(c), 14 or 15(d) of the Exchange Act after the date hereof and prior to the
filing of a post-effective amendment which deregisters all securities then
remaining unsold.

      ANY STATEMENT CONTAINED IN THIS REGISTRATION STATEMENT, OR IN A DOCUMENT
INCORPORATED OR DEEMED TO BE INCORPORATED BY REFERENCE HEREIN, SHALL BE DEEMED
TO BE MODIFIED OR SUPERSEDED FOR PURPOSES OF THIS REGISTRATION STATEMENT TO THE
EXTENT THAT A STATEMENT CONTAINED HEREIN, OR IN ANY OTHER SUBSEQUENTLY FILED
DOCUMENT WHICH ALSO IS INCORPORATED OR DEEMED TO BE INCORPORATED BY REFERENCE
HEREIN, MODIFIES OR SUPERSEDES SUCH STATEMENT. ANY SUCH STATEMENT SO MODIFIED OR
SUPERSEDED SHALL NOT BE DEEMED, EXCEPT AS SO MODIFIED OR SUPERSEDED, TO
CONSTITUTE A PART OF THIS REGISTRATION STATEMENT.

ITEM 4.  DESCRIPTION OF SECURITIES

      The Common Stock to be offered pursuant to the Plan has been registered
pursuant to Section 12(g) of the Exchange Act. Accordingly, a description of the
Common Stock is not required herein.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

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      None.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS AND PLAN ADMINISTRATOR

      The Registrant (also referred to herein as the "Subsidiary Holding
Company") shall indemnify its directors and employees in accordance with the
following provision from the Registrant's Bylaws:

                                  ARTICLE XII.
                                 INDEMNIFICATION

      The Subsidiary Holding Company shall indemnify all officers, directors and
employees of the Subsidiary Holding Company, and their heirs, executors and
administrators, to the fullest extent permitted under federal law against all
expenses and liabilities reasonably incurred by them in connection with or
arising out of any action, suit or proceeding in which they may be involved by
reason of their having been a director or officer of the Subsidiary Holding
Company, whether or not they continue to be a director or officer at the time of
incurring such expenses or liabilities, such expenses and liabilities to
include, but not be limited to, judgments, court costs and attorneys' fees and
the cost of reasonable settlements.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

      None.

ITEM 8.  EXHIBITS

      The following exhibits are filed with or incorporated by reference into
this registration statement on Form S-8 (numbering corresponds generally to the
Exhibit Table in Item 601 of Regulation S-K).

      List of Exhibits (filed herewith unless otherwise noted):

      5.0   Opinion of Muldoon Murphy & Aguggia LLP as to the legality of the 
            common stock to be issued.
      10.0  SI Financial Group, Inc. 2005 Equity Incentive Plan(1)
      23.1  Consent of Muldoon Murphy & Aguggia LLP
            (contained in the opinion included as Exhibit 5.0) 
      23.2  Consent of McGladrey & Pullen, LLP 
      24.0  Power of Attorney (contained on the signature pages).
------------------------------------
(1)   Incorporated herein by reference to Appendix B in the definitive 14A proxy
      statement (SEC No. 000-50801) filed with the SEC on April 6, 2005.

ITEM 9.  UNDERTAKINGS

      The undersigned Registrant hereby undertakes:

      (1)   To file, during any period in which offers or sales are being made,
            a post-effective amendment to this registration statement unless the
            information or prospectus required by (i) and (ii) is contained in
            periodic reports filed by the Registrant pursuant to Section

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            13(a) or 15(d) of the Exchange Act that are incorporated by
                  reference into this registration statement:

            (i)   To include any prospectus required by Section 10(a)(3) of the
                  Securities Act of 1933;

            (ii)  To reflect in the prospectus any facts or events arising after
                  the effective date of the registration statement (or the most
                  recent post-effective amendment thereof) which, individually
                  or in the aggregate, represent a fundamental change in the
                  information set forth in the registration statement; and

            (iii) To include any material information with respect to the plan
                  of distribution not previously disclosed in the registration
                  statement or any material change to such information in the
                  registration statement.

      (2)   That, for the purpose of determining any liability under the
            Securities Act of 1933, each such post-effective amendment shall be
            deemed to be a new registration statement relating to the securities
            offered therein, and the offering of such securities at that time
            shall be deemed to be the initial bona fide offering thereof; and

      (3)   To remove from registration by means of a post-effective amendment
            any of the securities being registered which remain unsold at the
            termination of the offering.

      (4)   That, for purposes of determining any liability under the Securities
            Act, each filing of the Registrant's annual report pursuant to
            Section 13(a) or 15(d) of the Exchange Act that is incorporated by
            reference in the registration statement shall be deemed to be a new
            registration statement relating to the securities offered therein,
            and the offering of such securities at that time shall be deemed to
            be the initial bona fide offering thereof.

      Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to trustees, officers and controlling persons of
the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that, in the opinion of the SEC, such
indemnification is against public policy as expressed in such Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the Registrant of expenses incurred
or paid by a trustee, officer or controlling person of the Registrant in the
successful defense of any action, suit or proceeding) is asserted by such
trustee, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question of whether such indemnification by it is against
public policy as expressed in such Act and will be governed by the final
adjudication of such issue.



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                                   SIGNATURES

      THE REGISTRANT.

      Pursuant to the requirements of the Securities Act of 1933, SI Financial
Group, Inc. certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8 and has duly caused this
registration statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in Willimantic, Connecticut on June 9, 2005.

                              SI Financial Group, Inc.


                              By: /s/ Rheo A. Brouillard 
                                  ----------------------------------------------
                                  Rheo A. Brouillard
                                  President and Chief Executive Officer
                                  (principal executive officer)

      KNOW ALL MEN BY THESE PRESENT, that each person whose signature appears
below (other than Mr. Brouillard) constitutes and appoints Mr. Brouillard as the
true and lawful attorney-in-fact and agent with full power of substitution and
resubstitution, for him or her and in his or her name, place and stead, in any
and all capacities to sign any or all amendments to the Form S-8 registration
statement, and to file the same, with all exhibits thereto, and other documents
in connection therewith, with the United States Securities and Exchange
Commission, granting unto said attorney-in-fact and agent full power and
authority to do and perform each and every act and thing requisite and necessary
to be done as fully, and to all intents and purposes, as he or she might or
could do in person, hereby ratifying and confirming all that said
attorney-in-fact and agent or his or her substitute, may lawfully do or cause to
be done by virtue hereof.

      Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities and on the dates indicated.


     Name                            Title                            Date
     ----                            -----                            ----


/s/ Rheo A. Brouillard       President, Chief Executive           June 9, 2005
-------------------------    Officer and Director
Rheo A. Brouillard           (principal executive officer)



/s/ Brian J. Hull            Executive Vice President and         June 9, 2005
-------------------------    Treasurer and Chief Financial Officer
Brian J. Hull                (principal accounting and
                             financial officer)




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/s/ Henry P. Hinckley        Chairman of the Board                June 9, 2005
--------------------------
Henry P. Hinckley



/s/ Robert C. Cushman, Sr.   Director                             June 9, 2005
--------------------------
Robert C. Cushman, Sr.



/s/ Mark D. Alliod           Director                             June 9, 2005
--------------------------
Mark D. Alliod



/s/ Donna M. Evan            Director                             June 9, 2005
--------------------------
Donna M. Evan



/s/ Roger Engle              Director                             June 9, 2005
--------------------------
Roger Engle



/s/ Robert O. Gillard        Director                             June 9, 2005
--------------------------
Robert O. Gillard



/s/ Steven H. Townsend       Director                             June 9, 2005
--------------------------
Steven H. Townsend



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                                  EXHIBIT INDEX




                                                                              Sequentially
                                                                                 Numbered
                                                                                   Page
Exhibit No.            Description                    Method of Filing           Location
---------    ------------------------------------  ---------------------      -------------
                                                   
  5.0        Opinion of Muldoon Murphy & Aguggia     Filed herewith.
             LLP

 10.0        SI Financial Group, Inc. 2005 Equity    Incorporated by reference.
             Incentive Plan

 23.1        Consent of Muldoon Murphy & Aguggia     Contained in the opinion
             LLP                                     included as Exhibit 5.0.

 23.2        Consent of McGladrey & Pullen, LLP      Filed herewith.

 24.0        Power of Attorney                       Located on the signature
                                                     page.





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