8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| North Eagle Butte | 1 | 1,594 | 1,838 | -1.48% | 181 | 9 | CDP |
| Eagle Butte | 2 | 1,275 | 1,249 | 0.39% | 936 | 1 | City |
| Timber Lake | 3 | 543 | 512 | 1.12% | 889 | 1 | City |
| La Plant | 4 | 332 | 305 | 3.11% | 35 | 9 | CDP |
| Swift Bird | 5 | 224 | 220 | 7.18% | 456 | 0 | CDP |
| Isabel | 6 | 157 | 146 | 1.29% | 186 | 1 | Town |
| Whitehorse | 7 | 148 | 245 | 0% | 54 | 3 | CDP |
| Lantry | 8 | 49 | 48 | 6.52% | 118 | 0 | CDP |
North Eagle Butte is the largest city in Dewey County, with a population of 1,594.
Lantry is the smallest city in Dewey County, with a population of 49.
There are 8 cities in Dewey County, South Dakota.