O'Reilly Automotive (ORLY) 10-Q 2011 Q2 Quarterly report

Exhibit 32.1 – CEO Certification

O’REILLY AUTOMOTIVE, INC. AND SUBSIDIARIES

O’REILLY AUTOMOTIVE, INC.

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the report of O’Reilly Automotive, Inc. (the “Company”) on Form 10-Q for the period ended June 30, 2011, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Greg Henslee, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Greg Henslee

Greg Henslee

Chief Executive Officer

(Principal Executive Officer)

August 8, 2011

The foregoing certification is being furnished as an exhibit to the Report pursuant to Item 601(b)(32) of Regulation S-K and Section 1350 of Title 18 of the United States Code and, accordingly, is not being filed with the Securities and Exchange Commission (the “Commission”) as part of the Report and is not to be incorporated by reference into any filing of the Company with the Commission, whether made before or after the date of the Report, irrespective of any general incorporation language contained in such filing.

A signed original of this written statement required by Section 906 of the Sarbanes-Oxley Act of 2002 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.