Exhibit 23.1
Consent of Independent Registered Public Accounting Firm
We consent to the incorporation by
reference in the Registration Statement (Form S-8 No. 333-145651) pertaining to the Allegheny
Technologies Retirement Savings Plan of our report dated June 25, 2009, with respect to the
financial statements and schedule of the Allegheny Technologies Retirement Savings Plan included in
this Annual Report (Form 11-K) for the year ended December 31, 2008.
/s/ Ernst & Young LLP
Pittsburgh, Pennsylvania
June 25, 2009