7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Twin Falls | 1 | 56,849 | 52,083 | 1.7% | 2,901 | 19.59 | City |
| Kimberly | 2 | 5,831 | 4,651 | 4.22% | 2,868 | 2.03 | City |
| Buhl | 3 | 4,813 | 4,567 | 1.03% | 2,561 | 1.88 | City |
| Filer | 4 | 3,079 | 2,759 | 2.12% | 2,096 | 1.47 | City |
| Hansen | 5 | 1,127 | 1,089 | 0.71% | 3,229 | 0.35 | City |
| Castleford | 6 | 232 | 217 | 1.31% | 2,417 | 0.10 | City |
| Murtaugh | 7 | 124 | 116 | 1.64% | 551 | 0.23 | City |
Twin Falls is the largest city in Twin Falls County, with a population of 56,849.
Murtaugh is the smallest city in Twin Falls County.
There are 7 cities in Twin Falls County, Idaho.