10 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sisseton | 1 | 2,411 | 2,473 | -0.41% | 1,515 | 2 | City |
| Wilmot | 2 | 422 | 433 | -0.47% | 792 | 1 | City |
| Rosholt | 3 | 368 | 380 | -0.54% | 1,243 | 0 | Town |
| Summit | 4 | 275 | 284 | -0.36% | 502 | 1 | Town |
| New Effington | 5 | 225 | 233 | -0.44% | 862 | 0 | Town |
| Peever | 6 | 173 | 176 | 0% | 1,395 | 0 | Town |
| Claire City | 7 | 81 | 84 | 0% | 443 | 0 | Town |
| Corona | 8 | 72 | 66 | 1.41% | 285 | 0 | Town |
| Ortley | 9 | 50 | 49 | 0% | 22 | 2 | Town |
| White Rock | 10 | 7 | 7 | 0% | 4 | 2 | Town |
Sisseton is the largest city in Roberts County, with a population of 2,411.
White Rock is the smallest city in Roberts County, with a population of 7.
There are 10 cities in Roberts County, South Dakota.