| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hardin | 1 | 3,677 | 3,794 | -0.51% | 1,237 | 3 | City |
| Lodge Grass | 2 | 420 | 437 | -0.47% | 1,628 | 0 | Town |
Hardin is the largest city in Big Horn County, with a population of 3,677.
Lodge Grass is the smallest city in Big Horn County, with a population of 420.
There are 2 cities in Big Horn County, Montana.