| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| White River | 1 | 595 | 537 | 1.19% | 1,142 | 1 | City |
| Wood | 2 | 49 | 42 | 2.08% | 199 | 0 | Town |
White River is the largest city in Mellette County, with a population of 595.
Wood is the smallest city in Mellette County, with a population of 49.
There are 2 cities in Mellette County, South Dakota.