18 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Caldwell | Canyon County | 79,260 |
| Coeur d'Alene | Kootenai County | 58,555 |
| Chubbuck | Bannock County | 17,032 |
| Cascade | Valley County | 1,038 |
| Council | Adams County | 1,023 |
| Cottonwood | Idaho County | 971 |
| Challis | Custer County | 967 |
| Carey | Blaine County | 709 |
| Clark Fork | Bonner County | 603 |
| Craigmont | Lewis County | 485 |
| Clifton | Franklin County | 481 |
| Culdesac | Nez Perce County | 418 |
| Cambridge | Washington County | 372 |
| Castleford | Twin Falls County | 232 |
| Crouch | Boise County | 189 |
| Conkling Park | Kootenai County | 161 |
| Coolin | Bonner County | 30 |
| Clayton | Custer County | 12 |