7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hailey | 1 | 10,234 | 9,208 | 2.04% | 2,603 | 3.93 | City |
| Ketchum | 2 | 3,644 | 3,561 | 0.47% | 1,137 | 3.21 | City |
| Bellevue | 3 | 2,582 | 2,564 | 0.15% | 1,735 | 1.49 | City |
| Sun Valley | 4 | 1,757 | 1,791 | -0.4% | 184 | 9.56 | City |
| Carey | 5 | 688 | 688 | 0% | 199 | 3.45 | City |
| Gannett | 6 | 395 | 388 | 7.05% | 151 | 2.62 | CDP |
| Acequia | 7 | 138 | 132 | 0.73% | 258 | 0.53 | City |
Hailey is the largest city in Blaine County, with a population of 10,234.
Acequia is the smallest city in Blaine County.
There are 7 cities in Blaine County, Idaho.