16 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Custer | 1 | 1,801 | 1,950 | -1.53% | 726 | 2 | City |
| Custer | 2 | 1,801 | 1,940 | -1.53% | 726 | 2 | City |
| Hermosa | 3 | 379 | 389 | -0.52% | 483 | 1 | Town |
| Hermosa | 4 | 379 | 387 | -0.52% | 483 | 1 | Town |
| Custer | 5 | 374 | 373 | 0% | 12 | 31 | Township |
| Custer | 6 | 374 | 374 | 0% | 12 | 31 | Township |
| Hill View Heights | 7 | 229 | 65 | 1.78% | 105 | 2 | CDP |
| Buffalo Gap | 8 | 160 | 128 | 3.9% | 523 | 0 | Town |
| Buffalo Gap | 9 | 160 | 129 | 3.9% | 523 | 0 | Town |
| Angostura | 10 | 148 | 75 | 7.25% | 12 | 13 | CDP |
| Pringle | 11 | 105 | 113 | -1.87% | 434 | 0 | Town |
| Pringle | 12 | 105 | 112 | -1.87% | 434 | 0 | Town |
| Fairburn | 13 | 70 | 57 | 2.94% | 214 | 0 | Town |
| Fairburn | 14 | 70 | 57 | 2.94% | 214 | 0 | Town |
| Custer | 15 | 27 | 28 | 0% | 1 | 51 | Township |
| Custer | 16 | 27 | 28 | 0% | 1 | 51 | Township |
Custer is the largest city in Custer County, with a population of 1,801.
Custer is the smallest city in Custer County, with a population of 27.
There are 16 cities in Custer County, South Dakota.