Exhibit 23 CONSENT OF INDEPENDENT ACCOUNTANTS We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (Nos. 33-47074; 33-47147; 33-57557; 33-63101; 333-66129; 333-72787 and 333-78953) of FirstMerit Corporation of our report dated January 16, 2003, relating to the consolidated financial statements, which appears in this Annual Report on Form 10K. /s/ PricewaterhouseCoopers, LLP Chicago, Illinois March 3, 2003