UNITED STATES
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): November 7, 2011

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

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

705 Westech Drive, Norcross, Georgia		30092
(Address of Principal Executive Offices)		(Zip Code)

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:

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

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

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

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 7.01 Regulation FD Disclosure.

S1 Corporation has posted a new investor presentation to its website, www.s1.com, in the “Investor Relations” section under the heading “About S1.” A copy of the investor presentation also is attached hereto as Exhibit 99.1.

The information contained in this Item 7.01, including the exhibit referenced herein, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities under Section 18.

Forward Looking Statements
Certain statements herein may constitute “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, those regarding any transaction with ACI Worldwide, Inc. and other statements that are not historical facts. These statements involve risks and uncertainties including those detailed in S1’s Annual Reports on Form 10-K and other filings with the Securities and Exchange Commission. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual outcomes may vary materially from those forecasted or expected. S1 disclaims any intention or obligation to update publicly or revise such statements, whether as a result of new information, future events or otherwise.

Additional Information and Where to Find It
S1 Corporation has filed a Solicitation/Recommendation Statement on Schedule 14D-9, as amended, with the SEC. INVESTORS AND STOCKHOLDERS ARE URGED TO READ THAT STATEMENT AND OTHER MATERIALS FILED WITH THE SEC BY S1 BECAUSE THEY CONTAIN IMPORTANT INFORMATION. S1 stockholders and other interested parties may obtain, free of charge, copies of S1’s Schedule 14D-9, as amended, and other documents filed by S1 with the SEC at the SEC’s website at http://www.sec.gov. In addition free copies of the documents filed by S1 with the SEC with respect to the exchange offer may be obtained by contacting S1’s Investor Relations at (404) 923-3500 or by accessing S1’s investor relations website at www.s1.com.

Item 9.01 Financial Statements and Exhibits.

(d)

Exhibits.

Exhibit No.		Description
99.1		Q3 2011 Earnings Call Presentation.

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.

EXHIBIT INDEX

Exhibit No.		Description
99.1		Q3 2011 Earnings Call Presentation.