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 31, 2012

Concho Resources Inc.

(Exact Name of Registrant as Specified in Its Charter)

Delaware

(State or Other Jurisdiction

of Incorporation)

Registrant’s telephone number, including area code: (432) 683-7443

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 31, 2012, Concho Resources Inc. (the “Company”) entered into a Ninth Amendment (the “Ninth Amendment”) to its Amended and Restated Credit Agreement, dated as of July 31, 2008, with the lenders party thereto and JPMorgan Chase Bank, N.A., as administrative agent (the “Amended and Restated Credit Agreement”).

The Ninth Amendment primarily provides for the increase of the lenders’ aggregate commitments under the Amended and Restated Credit Agreement from $2.0 billion to $2.5 billion. Following the Ninth Amendment, the Company will be able to have aggregate outstanding borrowings under the Amended and Restated Credit Agreement of up to the full $2.5 billion borrowing base.

The foregoing description of the Ninth Amendment is a summary only and is qualified in its entirety by reference to the complete text of the Ninth Amendment, a copy of which is attached as Exhibit 10.1 to this Current Report on Form 8-K and incorporated herein by reference.

The information set forth under Item 1.01 concerning the Ninth Amendment is incorporated herein by reference.

(d) 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