15 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Boise City | Ada County | 238,923 |
| Blackfoot | Bingham County | 13,631 |
| Burley | Cassia County | 12,435 |
| Buhl | Twin Falls County | 4,856 |
| Bonners Ferry | Boundary County | 2,914 |
| Bellevue | Blaine County | 2,591 |
| Blanchard | Bonner County | 709 |
| Basalt | Bingham County | 383 |
| Bancroft | Caribou County | 323 |
| Bliss | Gooding County | 269 |
| Bloomington | Bear Lake County | 223 |
| Bovill | Latah County | 207 |
| Bennington | Bear Lake County | 104 |
| Butte City | Butte County | 89 |
| Bruneau | Owyhee County | 44 |