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): May 3, 2013

The Hackett Group, Inc.

(Exact name of registrant as specified in its charter)

(305) 375-8005

(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. below):

On May 7, 2013, The Hackett Group, Inc. (the “Company”) issued a press release setting forth its consolidated financial results for the first fiscal quarter of 2013. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated by reference herein.

The information contained in Item 2.02 of this current report on Form 8-K, as well as Exhibit 99.1, is being furnished to the Securities and Exchange Commission and shall not be deemed “filed” with the Securities and Exchange Commission nor incorporated by reference in any registration statement filed by the Company under the Securities Act of 1933, as amended.

The 2013 Annual Meeting of Shareholders of the Company was held on May 3, 2013. Matters submitted to shareholders at the meeting and the voting results thereof were as follows:

Proposal 1 – Election of Directors. The shareholders of the Company elected each of the director nominees named below to serve until the 2016 Annual Meeting of Shareholders and until their successors are duly elected and qualified. The following is a breakdown of the voting results:

Proposal 2 – Amendment to the Company’s 1998 Stock Option and Incentive Plan. The shareholders of the Company approved to (i) increase the sublimit under the Plan for issuances of restricted stock and restricted stock units by 1,230,237, and (ii) reduce the total number of shares available for issuance under the Plan by 1,932,464 shares, as well as to re-approve the performance criteria under the Plan to maintain deductibility for the purposes of Code Section 162(m). The following is a breakdown of voting results:

Proposal 3 – Advisory Vote on Executive Compensation. The shareholders of the Company approved an advisory vote on executive compensation. The following is a breakdown of the voting results:

Proposal 4 – Appointment of BDO USA, LLP as Independent Auditor. The shareholders of the Company ratified the appointment of BDO USA, LLP as the Company’s independent registered public accounting firm for the 2013 fiscal year. The following is a breakdown of the voting results:

Item 9.01 Financial Statements and Exhibits.

See Exhibit Index attached hereto.

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