Towns
| State | City/Town | Town Title |
|---|---|---|
| Illinois | Camp Point | Camp Point, IL |
| Illinois | Campbell Hill | Campbell Hill, IL |
| Illinois | Campus | Campus, IL |
| Illinois | Canton | Canton, IL |
| Illinois | Cantrall | Cantrall, IL |
| Illinois | Capron | Capron, IL |
| Illinois | Carbon Cliff | Carbon Cliff, IL |
| Illinois | Carbondale | Carbondale, IL |
| Illinois | Carlinville | Carlinville, IL |
| Illinois | Carlock | Carlock, IL |
| Illinois | Carlyle | Carlyle, IL |
| Illinois | Carman | Carman, IL |
| Illinois | Carmi | Carmi, IL |
| Illinois | Carol Stream | Carol Stream, IL |
| Illinois | Carpentersville | Carpentersville, IL |
| Illinois | Carrier Mills | Carrier Mills, IL |
| Illinois | Carrollton | Carrollton, IL |
| Illinois | Carterville | Carterville, IL |
| Illinois | Carthage | Carthage, IL |
| Illinois | Cary | Cary, IL |
| Illinois | Casey | Casey, IL |
| Illinois | Caseyville | Caseyville, IL |
| Illinois | Castleton | Castleton, IL |
| Illinois | Catlin | Catlin, IL |
| Illinois | Cave In Rock | Cave In Rock, IL |