11 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Thompson Falls | 1 | 1,560 | 1,340 | 2.9% | 979 | 1.59 | City |
| Plains | 2 | 1,296 | 1,111 | 2.94% | 2,107 | 0.61 | Town |
| Hot Springs | 3 | 653 | 563 | 2.83% | 1,701 | 0.38 | Town |
| Trout Creek | 4 | 312 | 205 | 1.63% | 169 | 1.84 | CDP |
| Dixon | 5 | 309 | 252 | 2.32% | 47 | 6.63 | CDP |
| Heron | 6 | 303 | 281 | 0.33% | 59 | 5.09 | CDP |
| Noxon | 7 | 202 | 162 | -0.49% | 163 | 1.24 | CDP |
| Lonepine | 8 | 141 | 129 | -0.7% | 10 | 13.44 | CDP |
| Paradise | 9 | 121 | 114 | -1.63% | 490 | 0.25 | CDP |
| Weeksville | 10 | 120 | 86 | 7.14% | 41 | 2.91 | CDP |
| Old Agency | 11 | 80 | 61 | -1.23% | 141 | 0.57 | CDP |
Thompson Falls is the largest city in Sanders County, with a population of 1,560.
Old Agency is the smallest city in Sanders County.
There are 11 cities in Sanders County, Montana.