5 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Lewistown | 1 | 6,262 | 5,971 | 0.93% | 1,094 | 6 | City |
| Denton | 2 | 213 | 206 | 0.47% | 299 | 1 | Town |
| Moore | 3 | 203 | 193 | 1% | 695 | 0 | Town |
| Winifred | 4 | 177 | 171 | 0.57% | 338 | 1 | Town |
| Grass Range | 5 | 116 | 110 | 0.87% | 829 | 0 | Town |
Lewistown is the largest city in Fergus County, with a population of 6,262.
Grass Range is the smallest city in Fergus County, with a population of 116.
There are 5 cities in Fergus County, Montana.