Exhibit 23.3 Consent of Independent Auditors We consent to the reference to our firm under the caption "Experts" in the Registration Statement (Form S-4) and related Prospectus of First Bank System, Inc. for the registration of 517,241 shares of its common stock and to the incorporation by reference therein of our report dated January 24, 1995, with respect to the consolidated financial statements of First Bank System, Inc. included in its Current Report on Form 8-K dated March 3, 1995, filed with the Securities and Exchange Commission. /s/ Ernst & Young LLP Minneapolis, Minnesota August 29, 1995