SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 8-K
                                 CURRENT REPORT


                     Pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934


         Date of Report (Date of earliest event reported): March 3, 2005



                                 S1 CORPORATION
                                 --------------
             (Exact name of registrant as specified in its charter)



           Delaware                     000-24931            58-2395199
           --------                     ---------            -----------
 (State or other jurisdiction          (Commission          (IRS Employer
       of incorporation)               File Number)        Identification No.)



               3500 Lenox Road, Suite 200, Atlanta, Georgia 30326
               --------------------------------------------------
                    (Address of principal executive offices)


       Registrant's telephone number, including area code: (404) 923-3500
                                                           --------------


                                 Not Applicable
- --------------------------------------------------------------------------------
          (Former name or former address, if changed since last report)



Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2. below):

|_|  Written communications pursuant to Rule 425 under the Securities Act
    (17 CFR 230.425)

|_|  Soliciting material pursuant to Rule 14a-12 under the Exchange Act
     (17 CFR 240.14a-12)

|_|  Pre-commencement communications pursuant to Rule 14d-2(b) under the
     Exchange Act (17 CFR 240.14d-2(b))

|_|  Pre-commencement communications pursuant to Rule 13e-4(c) under the
     Exchange Act (17 CFR 240.13e-4(c)) Rule 425, Rule 14a-12 and Instruction 2
     to Rule 14d-2(b)(2)







Item 2.02   Results of Operations and Financial Condition
- ---------------------------------------------------------

         On March 3, 2005, S1 Corporation ("S1") issued a press release
announcing the results of operations for the quarter and year ended December 31,
2004. That press release is filed as Exhibit 99.1 to this report. Also on March
3, 2005, S1 held a conference call during which S1 discussed its fourth quarter
and year end results and presented certain other material relating to S1 and its
operations. A replay of the conference call is available for playback two hours
after the conference call is complete by dialing (800) 642-1687, Access #
3925458. The replay will be active until 5:00 p.m. EDT on March 10, 2005.

            In accordance with General Instruction B.2 of Form 8-K, the
information in this Current Report on Form 8-K, including Exhibit 99.1, shall
not be deemed "filed" for the purposes of Section 18 of the Securities Exchange
Act of 1934, as amended, or otherwise subject to the liability of that section,
nor shall it be deemed incorporated by reference in any filing under the
Securities Act of 1933, as amended, except as shall be expressly set forth by
specific reference in such a filing.


Item 9.01 Financial Statements and Exhibits
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(c) Exhibits


Exhibit No.                Description
- ----------                 -----------
     99.1                  Press release dated March 3, 2005.











                                   SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                    S1 CORPORATION
                                    ----------------------------------------
                                    (Registrant)




                                    /s/ Richard P. Dobb
                                    ----------------------------------------
                                    Richard P. Dobb
                                    Vice President, General Counsel and
                                    Secretary





Date: March 3, 2005







                                  EXHIBIT INDEX



         Exhibit No.       Description
         -----------       -----------
         99.1              Press release dated March 3, 2005.