7 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Twin Falls | 1 | 57,325 | 52,116 | 1.54% | 2,885 | 20 | City |
| Kimberly | 2 | 6,061 | 4,653 | 4.03% | 2,981 | 2 | City |
| Buhl | 3 | 4,856 | 4,570 | 1% | 2,584 | 2 | City |
| Filer | 4 | 3,166 | 2,787 | 2.03% | 2,155 | 1 | City |
| Hansen | 5 | 1,131 | 1,091 | 0.62% | 3,241 | 0 | City |
| Castleford | 6 | 232 | 214 | 1.31% | 2,417 | 0 | City |
| Murtaugh | 7 | 127 | 115 | 1.6% | 564 | 0 | City |
Twin Falls is the largest city in Twin Falls County, with a population of 57,325.
Murtaugh is the smallest city in Twin Falls County, with a population of 127.
There are 7 cities in Twin Falls County, Idaho.