As filed with the Securities and Exchange Commission on December 21, 2007
                                                    Registration No. 333-144245

                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                         POST-EFFECTIVE AMENDMENT NO. 1
                                     TO THE

                                    FORM S-1
                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                         UNITED FINANCIAL BANCORP, INC.
             (Exact Name of Registrant as Specified in Its Charter)


          Maryland                           6712                   74-3242562
 (State or Other Jurisdiction of  (Primary Standard Industrial  (I.R.S. Employer
 Incorporation or Organization)    Classification Code Number)   Identification
                                                                  Number)


                                  95 Elm Street
                      West Springfield, Massachusetts 01089
                                 (413) 787-1700
   (Address, Including Zip Code, and Telephone Number, Including Area Code, of
                    Registrant's Principal Executive Offices)

                               Richard B. Collins
                                  95 Elm Street
                      West Springfield, Massachusetts 01089
                                 (413) 787-1700
   (Address, Including Zip Code, and Telephone Number, Including Area Code, of
                               Agent for Service)

                                   Copies to:
                            Robert B. Pomerenk, Esq.
                                 Eric Luse, Esq.
                             Robert I. Lipsher, Esq.
                       Luse Gorman Pomerenk & Schick, P.C.
                     5335 Wisconsin Avenue, N.W., Suite 400
                             Washington, D.C. 20015
                                 (202) 274-2000







PART II: INFORMATION  NOT  REQUIRED  IN PROSPECTUS


                         Deregistration of Common Stock

     This   Post-Effective   Amendment  No.  1  is  filed  for  the  purpose  of
deregistering  16,631,162 shares of the $.01 par value common stock (the "Common
Stock")  of  United  Financial  Bancorp,   Inc.,  a  Maryland  corporation  (the
"Company"),  heretofore  registered  and  offered  pursuant  to the terms of the
Prospectus  dated  October  12,  2007 and the Proxy  Statement/Prospectus  dated
October 12, 2007. The Company previously  registered 34,395,529 shares of Common
Stock. The remaining  17,764,367 shares registered pursuant to this Registration
Statement on Form S-1 have been issued in accordance  with (i) the Prospectus in
the  subscription,   community  and  syndicated  community  offerings  described
therein,  and (ii)  the  Proxy  Statement/Prospectus  in the  exchange  offering
described therein. The offering was completed on December 3, 2007.

     The Company has determined  that no further  shares will be offered,  sold,
issued   and/or   exchanged   pursuant   to  the   Prospectus   and  the   Proxy
Statement/Prospectus.  The  Company  therefore  requests  deregistration  of the
unissued shares of Common Stock pursuant to this Registration  Statement as soon
as practicable after the filing of this Post-Effective Amendment No. 1.

                                      II-1







                                   SIGNATURES


     Pursuant to the  requirements of the Securities Act of 1933, the registrant
has duly caused this  registration  statement  to be signed on its behalf by the
undersigned,  thereunto  duly  authorized,  in the  City  of  West  Springfield,
Commonwealth of Massachusetts, on December 20, 2007.

                                        UNITED FINANCIAL BANCORP, INC.


                                        By:  /s/ Richard B. Collins
                                             -------------------------------
                                             Richard B. Collins
                                             Chairman, President and Chief
                                             Executive Officer
                                             (Duly Authorized Representative)

                                POWER OF ATTORNEY

     We, the  undersigned  directors and officers of United  Financial  Bancorp,
Inc. (the "Company"), hereby severally constitute and appoint Richard B. Collins
as our true and lawful attorney and agent, to do any and all things in our names
in the  capacities  indicated  below  which  said  Richard B.  Collins  may deem
necessary or advisable to enable the Company to comply with the  Securities  Act
of 1933,  and any rules,  regulations  and  requirements  of the  Securities and
Exchange Commission,  in connection with the registration  statement on Form S-1
relating to the offering of the Company's common stock, including  specifically,
but not  limited  to,  power  and  authority  to sign for us in our names in the
capacities indicated below the registration statement and any and all amendments
(including post-effective amendments) thereto; and we hereby approve, ratify and
confirm all that said Richard B. Collins  shall do or cause to be done by virtue
thereof.


     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.



                                                                        


            Signatures                          Title                                   Date
            ----------                          -----                                   ----

/s/ Richard B. Collins                   Chairman, President and Chief
------------------------------------     Executive Officer                          December 20, 2007
Richard B. Collins                       (Principal Executive Officer)


/s/ Mark A. Roberts                      Execuitve Vice President and
------------------------------------     Chief Financial Officer                    December 20, 2007
Mark A. Roberts                          (Principal Financial and
                                         Accounting Officer)



/s/ Michael F. Crowley                   Director                                   December 20, 2007
------------------------------------
Michael F. Crowley


/s/ Carol Moore Cutting                  Director                                   December 20, 2007
------------------------------------
Carol Moore Cutting


/s/ Carol A. Leary                       Director                                   December 20, 2007
------------------------------------
Carol A. Leary



/s/ G. Todd Marchant                     Director                                   December 20, 2007
------------------------------------
G. Todd Marchant


/s/ Kevin E. Ross                        Director                                   December 20, 2007
------------------------------------
Kevin E. Ross

/s/ Robert A. Steward, Jr.               Director                                   December 20, 2007
-------------------------------
Robert A. Stewart, Jr.


/s/ Thomas H. Themistos                  Director                                   December 20, 2007
-------------------------------
Thomas H. Themistos


/s/ Michael F. Werenski                  Director                                   December 20, 2007
-------------------------------
Michael F. Werenski