EXHIBIT 23 CONSENT OF INDEPENDENT AUDITORS We consent to the incorporation by reference of our report dated February 27, 2003, with respect to the consolidated financial statements and schedule of Kerr-McGee Corporation included in the Annual Report (Form 10-K) for the year ended December 31, 2002, in the following registration statements and related prospectuses: Kerr-McGee Performance Share Plan Kerr-McGee Corporation Executive Deferred Compensation Plan Form S-8 File No. 333-66436 Oryx Energy Company 1997 Long Term Incentive Plan Oryx Energy Company Executive Variable Incentive Plan Oryx Energy Company Equity and Deferred Compensation Plan for Non-Employee Directors Form S-8 File No. 333-66438 Kerr-McGee Corporation Savings Investment Plan Kerr-McGee Corporation Employee Stock Ownership Plan HS Resources, Inc. Employee Investment 401(k) and Profit Sharing Plan Form S-8 File No. 333-66440 Kerr-McGee Corporation Long Term Incentive Program Kerr-McGee Corporation 1998 Long Term Incentive Plan Kerr-McGee Corporation 2000 Long Term Incentive Plan Form S-8 File No. 333-66442 Kerr-McGee Corporation 2002 Long Term Incentive Plan Form S-8 File No. 333-89558 Oryx Energy Company 1997 Long Term Incentive Plan Oryx Energy Company Executive Variable Incentive Plan Oryx Energy Company Equity and Deferred Compensation Plan for Non-Employee Directors Form S-8 File No. 333-41008 Kerr-McGee Corporation 2000 Long Term Incentive Plan Form S-8 File No. 333-41006 Kerr-McGee Corporation Executive Deferred Compensation Plan Form S-8 File No. 333-41000 Kerr-McGee Corporation 1998 Long Term Incentive Plan Form S-8 File No. 333-39222 Kerr-McGee Corporation Performance Share Plan Form S-8 File No. 333-92865 Kerr-McGee Corporation Long Term Incentive Program Form S-8 File No. 333-05999 Kerr-McGee Corporation Long Term Incentive Program Form S-8 File No. 33-50949 Kerr-McGee Corporation Long Term Incentive Program Form S-8 File No. 33-24274 Kerr-McGee Corporation Form S-3 File No. 333-81720 /s/ ERNST & YOUNG LLP Oklahoma City, Oklahoma March 24, 2003