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

March 3, 2016

(Date of earliest event reported)

Callon Petroleum Company

(Exact name of registrant as specified in its charter)

200 North Canal St.

Natchez, Mississippi 39120

(Address of principal executive offices, including zip code)

(601) 442-1601

(Registrant’s telephone number, including area code)

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):

Section 1 — Registrant’s Business and Operations

On March 3, 2016, Callon Petroleum Company (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Credit Suisse Securities (USA) LLC and J.P. Morgan Securities LLC (collectively, the “Underwriters”), providing for the offer and sale in a firm commitment offering of 13,265,000 shares of the Company’s common stock, par value $0.01 per share (the “Common Stock”), at a public offering price of $6.50 per share of Common Stock. Pursuant to the Underwriting Agreement, the Company granted the Underwriters a 30-day option to purchase up to 1,985,000 additional shares of Common Stock at the same price. The offer and sale of the Common Stock is registered under the Securities Act of 1933, as amended (the “Securities Act”), pursuant to a Registration Statement on Form S-3 (File No. 333-202038), which was declared effective by the Securities and Exchange Commission on February 23, 2015. The Company expects the transaction to close on or about March 9, 2016.

In the Underwriting Agreement, the Company agreed to indemnify the Underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the Underwriters may be required to make because of any of those liabilities. The foregoing description of the Underwriting Agreement is qualified by reference to the complete document, which is filed as Exhibit 1.1 to this Form 8-K and is incorporated herein by reference.

Section 7 — Regulation FD

On March 3, 2016 the Company issued a press release announcing that it had priced the offering of the 13,265,000 shares of Common Stock. A copy of the press release is furnished as Exhibit 99.1 hereto and is incorporated herein by reference.

The information set forth in the attached Exhibit 99.1 shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or incorporated by reference in any filing under the Securities Act or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Section 9 — Financial Statements and Exhibits

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