11 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Ammon | Bonneville County | 21,204 |
| American Falls | Power County | 5,011 |
| Aberdeen | Bingham County | 1,902 |
| Avimor | Ada County | 1,586 |
| Ashton | Fremont County | 983 |
| Arco | Butte County | 927 |
| Athol | Kootenai County | 752 |
| Arbon Valley | Bannock County | 605 |
| Arimo | Bannock County | 367 |
| Albion | Cassia County | 264 |
| Acequia | Blaine County | 139 |