1 Exhibit 21 DIRECT AND INDIRECT SUBSIDIARIES OF FIRSTMERIT CORPORATION* Citizens Investment Corporation Citizens Savings Corporation of Stark County FirstMerit Bank, N.A. - Abell & Associates, Inc. - Alpha Equipment Group, Inc. - FirstMerit Insurance Agency, Inc. - FirstMerit Leasing Company - FirstMerit Mortgage Corporation - FirstMerit Securities, Inc. - Home Financial Services Corp. - Mobile Consultants, Inc. - OPN, Inc. - NB 5 Financial Services, Inc. - Professional Appraisal Services Corp. - Signal Finance Company - FirstMerit Commercial Insurance Agency, Inc. - Signal R. Corp. (Delaware) - Signal Securitization Corp. (Delaware) FirstMerit Capital Trust I (Delaware) FirstMerit Community Development Corporation FirstMerit Credit Life Insurance Company (Arizona) SF Development Corp. - Richwood Development (50%) - Rushmore Subdivision Ltd. (50%) - Courts of Weymouth Development, Ltd. (33%) * Unless otherwise indicated, state of formation is Ohio and subsidiary is wholly owned.