| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Arco | 1 | 925 | 878 | 0.76% | 866 | 1 | City |
| Moore | 2 | 179 | 160 | 1.7% | 630 | 0 | City |
| Butte City | 3 | 88 | 80 | 1.15% | 521 | 0 | City |
Arco is the largest city in Butte County, with a population of 925.
Butte City is the smallest city in Butte County, with a population of 88.
There are 3 cities in Butte County, Idaho.