| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Custer | 1 | 1,776 | 1,934 | -1.5% | 716 | 2 | City |
| Hermosa | 2 | 368 | 382 | -0.54% | 425 | 1 | Town |
| Buffalo Gap | 3 | 161 | 128 | 3.87% | 526 | 0 | Town |
| Pringle | 4 | 102 | 110 | -1.92% | 421 | 0 | Town |
| Fairburn | 5 | 71 | 57 | 2.9% | 217 | 0 | Town |
Custer is the largest city in Custer County, with a population of 1,776.
Fairburn is the smallest city in Custer County, with a population of 71.
There are 5 cities in Custer County, South Dakota.