18 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Caldwell | Canyon County | 76,174 |
| Coeur | Kootenai County | 57,955 |
| Chubbuck | Bannock County | 16,804 |
| Cascade | Valley County | 1,032 |
| Council | Adams County | 999 |
| Challis | Custer County | 955 |
| Cottonwood | Idaho County | 946 |
| Carey | Blaine County | 706 |
| Clark Fork | Bonner County | 589 |
| Craigmont | Lewis County | 481 |
| Clifton | Franklin County | 471 |
| Culdesac | Nez Perce County | 417 |
| Cambridge | Washington County | 368 |
| Castleford | Twin Falls County | 229 |
| Crouch | Boise County | 184 |
| Conkling Park | Kootenai County | 163 |
| Clayton | Custer County | 12 |
| Coolin | Bonner County | 11 |