UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 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): June 10, 2016

Bank of the Ozarks, Inc.

(Exact name of registrant as specified in its charter)

Arkansas

(State or other jurisdiction

of incorporation)

(501) 978-2265

(Registrant’s telephone number, including area code)

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.):

On October 19, 2015, Bank of the Ozarks, Inc. (“Company”) announced the signing of a definitive agreement and plan of merger (“Merger Agreement”) with Community & Southern Holdings, Inc. (“C&S”) whereby the Company would acquire C&S and its wholly-owned bank subsidiary, Community & Southern Bank (collectively, the “Merger”). The terms of the Merger and the Merger Agreement are more fully described in the Company’s Current Report on Form 8-K dated October 19, 2015. The proposed Merger has not yet been consummated and there can be no assurance that the transaction will be consummated as contemplated.

We are filing herewith (i) historical audited financial statements of C&S for the year ended December 31, 2015 and 2014, (ii) historical unaudited financial statements of C&S for the three months ended March 31, 2016 and 2015, and (iii) the unaudited pro forma combined consolidated financial information of the Company, C&S and C1 Financial, Inc.

Cautionary Note Regarding Forward-Looking Statements

Statements in this Current Report on Form 8-K, including the pro forma combined financial information attached hereto contain “forward-looking statements” within the meaning of the federal securities laws, including the Private Securities Litigation Reform Act of 1995. The pro forma combined financial information is based on preliminary estimates and assumptions that could cause actual results to differ materially from those expected or implied by the pro forma combined financial information or the estimates and assumptions used in preparing the pro forma combined financial information. The pro forma combined financial information and forward-looking statements are based on current expectations and projections about future events. Investors are cautioned that forward-looking statements are not guarantees of future performance or results and involve risks and uncertainties that cannot be predicted or quantified and, consequently, the actual performance of the Company may differ materially from that expressed or implied by such forward-looking statements. Certain factors that could cause actual results to differ materially from the Company’s expectations include the risks detailed under “Item 1A. Risk Factors” contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 and in the other documents the Company files with the SEC. Many of these factors are beyond the Company’s ability to control or predict. Forward-looking statements are not guarantees of performance

Audited financial statements of Community & Southern Holdings, Inc. as of December 31, 2015 and 2014 and the notes related thereto, are filed herewith as Exhibit 99.1 and incorporated in this Item 9.01(a) by reference.

Unaudited financial statements of Community & Southern Holdings, Inc. for the three months ended March 31, 2016 and 2015, and the notes related thereto, are filed herewith as Exhibit 99.2 and incorporated in this Item 9.01(a) by reference.

Unaudited pro forma combined consolidated financial statements of Bank of the Ozarks, Inc. for the year ended December 31, 2015 and the three months ended March 31, 2016 are filed herewith as Exhibit 99.3, and incorporated in this Item 9.01(b) by reference.

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