11 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Ammon | Bonneville County | 20,778 |
| American Falls | Power County | 4,927 |
| Aberdeen | Bingham County | 1,897 |
| Avimor | Ada County | 1,642 |
| Arco | Butte County | 962 |
| Ashton | Fremont County | 951 |
| Arbon Valley | Bannock County | 830 |
| Athol | Kootenai County | 750 |
| Arimo | Bannock County | 348 |
| Albion | Cassia County | 251 |
| Acequia | Blaine County | 138 |