Courts Directory | State of Illinois Office of the Illinois Courts Whiteside County Courthouse Circuit District: 4 | Circuit: 14thWhiteside County 200 East Knox StreetMorrison, IL - Illinois 61270 815-772-5170 Visit Website Links Resources Court Disability Coordinator Sue Costello, Circuit Clerk - 14th Judicial Circuit, (815) 772-5170, scostello@whiteside.org