Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the reference to our firm under the caption “Experts” in the Registration Statement (Form S-3) and related Prospectus of Reliance Steel & Aluminum Co. dated July 17, 2008, for the registration of shares of its common stock and to the incorporation by reference therein of our reports dated February 28, 2008, with respect to the consolidated financial statements and schedule of Reliance Steel & Aluminum Co., and the effectiveness of internal control over financial reporting of Reliance Steel & Aluminum Co., included in its Annual Report (Form 10-K) for the year ended December 31, 2007, filed with the Securities and Exchange Commission.

/s/ ERNST & YOUNG LLP

Los Angeles, California
July 16, 2008