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) September 28, 2011

SunTrust Banks, Inc.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (404) 588-7711

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):

Item 8.01. Other Events.

On September 28, 2011, the United States Department of the Treasury (“Treasury”) closed the secondary public offerings of 6,008,902 warrants (the “Series A Warrants”) and 11,891,280 warrants (the “Series B Warrants”, and together with the Series A Warrants, the “Warrants”). The Series A Warrants and the Series B Warrants represent the right to purchase an aggregate of up to that same number of SunTrust Banks, Inc.’s (“SunTrust” or the “Company”) common stock, par value $1.00 per share, at an exercise price of $33.70 and $44.15 per share, respectively. The Warrants were offered pursuant to separate underwriting agreements (the “Underwriting Agreements”) dated September 22, 2011, each among the Company, Treasury and Deutsche Bank Securities Inc. as the representative (the “Representative”) of the underwriters. The public offering price and the allocation of the Warrants in these offerings were determined by an auction process. The public offering price of the Series A Warrants and Series B Warrants was equal to their respective auction clearing prices of $2.70 and $1.20. The Company did not receive any of the proceeds of the offerings of the Warrants. Each offering was made only under a prospectus supplement and the accompanying prospectus filed with the Securities and Exchange Commission (the “Commission”) pursuant to the Company’s automatic shelf registration statement on Form S-3 (Registration No. 333-161712).

In connection with these offerings, the Company and certain of its officers and directors have agreed to enter into 45-day “lock-up” agreements in substantially the form included in the Underwriting Agreements and subject to customary exceptions. Additionally, the Company entered into warrant agreements with respect to the each of the Series A Warrants and Series B Warrants, dated September 22, 2011 (the “Warrant Agreements”), among the Company and Computershare Inc. and Computershare Trust Company, N.A., together, as warrant agent.

The foregoing description of the Underwriting Agreements, Warrant Agreements, the Warrants and other documents relating to these transactions does not purport to be complete and is qualified in its entirety by reference to the full text of these documents and securities, forms or copies of which are incorporated by reference or are attached as exhibits to this Current Report on Form 8-K and are incorporated herein by reference.

The Representative and its affiliates have, from time to time, provided, and may in the future provide, various investment banking and financial advisory services to the Company, for which it received or will receive customary fees and expenses.

Exhibits 4.1, 4.2, 4.3, 4.4, 5.1, 5.2, 23.1 and 23.2 to this Current Report on Form 8-K are filed herewith in connection with SunTrust’s effective registration statement on Form S-3 (Registration No. 333-161712) and are incorporated herein by reference.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

SIGNATURE

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 thereunto duly authorized.

EXHIBIT INDEX