18 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Caldwell | Canyon County | 73,466 |
| Coeur | Kootenai County | 58,195 |
| Chubbuck | Bannock County | 16,824 |
| Cascade | Valley County | 1,020 |
| Council | Adams County | 1,009 |
| Cottonwood | Idaho County | 971 |
| Challis | Custer County | 944 |
| Carey | Blaine County | 688 |
| Clark Fork | Bonner County | 588 |
| Craigmont | Lewis County | 496 |
| Clifton | Franklin County | 480 |
| Culdesac | Nez Perce County | 426 |
| Cambridge | Washington County | 364 |
| Castleford | Twin Falls County | 232 |
| Crouch | Boise County | 189 |
| Conkling Park | Kootenai County | 163 |
| Coolin | Bonner County | 11 |
| Clayton | Custer County | 10 |