- Cabery
- Cahokia
- Calumet City
- Calumet Park
- Camp Point
- Campbell Hill
- Campus
- Cantrall
- Carbon Cliff
- Carlinville
- Carlock
- Carmi
- Carol Stream
- Carpentersville
- Carrier Mills
- Carterville
- Casey
- Caseyville
- Catlin
- Cave-in-Rock
- Chadwick
- Champaign
- Chandlerville
- Channahon
- Channel Lake
- Chebanse
- Chenoa
- Cherry
- Chicago
- Chicago Heights
