| City | County | 2026 Pop. ↓ |
|---|---|---|
| Ammon | Bonneville County | 20,681 |
| American Falls | Power County | 4,852 |
| Aberdeen | Bingham County | 1,875 |
| Avimor | Ada County | 1,586 |
| Ashton | Fremont County | 977 |
| Arco | Butte County | 925 |
| Athol | Kootenai County | 745 |
| Arbon Valley | Bannock County | 605 |
| Arimo | Bannock County | 364 |
| Albion | Cassia County | 271 |
| Acequia | Blaine County | 135 |