19 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fort Benton | 1 | 1,413 | 1,457 | -0.63% | 616 | 2 | City |
| Fort Benton | 2 | 1,413 | 1,456 | -0.63% | 616 | 2 | City |
| Rocky Boy West | 3 | 949 | 836 | 0.42% | 174 | 5 | CDP |
| Big Sandy | 4 | 599 | 624 | -0.83% | 1,256 | 0 | Town |
| Big Sandy | 5 | 599 | 623 | -0.83% | 1,256 | 0 | Town |
| Sangrey | 6 | 550 | 418 | 3% | 87 | 6 | CDP |
| St. Pierre | 7 | 452 | 357 | 1.35% | 56 | 8 | CDP |
| Azure | 8 | 411 | 431 | 1.99% | 91 | 4 | CDP |
| Parker School | 9 | 399 | 659 | 1.01% | 54 | 7 | CDP |
| Boneau | 10 | 261 | 290 | -2.97% | 110 | 2 | CDP |
| Geraldine | 11 | 204 | 211 | -0.97% | 356 | 1 | Town |
| Geraldine | 12 | 204 | 211 | -0.97% | 356 | 1 | Town |
| Highwood | 13 | 180 | 229 | 0% | 35 | 5 | CDP |
| Rocky Boy's Agency | 14 | 166 | 353 | -7.26% | 19 | 9 | CDP |
| Carter | 15 | 117 | 99 | 6.36% | 40 | 3 | CDP |
| Loma | 16 | 101 | 121 | 7.45% | 29 | 3 | CDP |
| Midway Colony | 17 | 40 | 74 | 8.11% | 76 | 1 | CDP |
| Floweree | 18 | 27 | 11 | 3.85% | 23 | 1 | CDP |
| Square Butte | 19 | 26 | 14 | 8.33% | 95 | 0 | CDP |
Fort Benton is the largest city in Chouteau County, with a population of 1,413.
Square Butte is the smallest city in Chouteau County, with a population of 26.
There are 19 cities in Chouteau County, Montana.