7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Horseshoe Bend | 1 | 856 | 725 | 3.13% | 787 | 1 | City |
| Idaho City | 2 | 552 | 471 | 2.99% | 830 | 1 | City |
| Garden Valley | 3 | 413 | 475 | 0.24% | 56 | 7 | CDP |
| Crouch | 4 | 184 | 159 | 2.79% | 372 | 0 | City |
| Placerville | 5 | 48 | 46 | 0% | 48 | 1 | City |
| Lowman | 6 | 27 | 14 | 3.85% | 13 | 2 | CDP |
| Banks | 7 | 6 | 6 | 0% | 3 | 2 | CDP |
Horseshoe Bend is the largest city in Boise County, with a population of 856.
Banks is the smallest city in Boise County, with a population of 6.
There are 7 cities in Boise County, Idaho.