6 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Yankton | 1 | 15,792 | 15,426 | 0.39% | 1,816 | 9 | City |
| Gayville | 2 | 374 | 388 | -0.53% | 1,824 | 0 | Town |
| Mission Hill | 3 | 177 | 191 | -1.12% | 540 | 0 | Town |
| Volin | 4 | 158 | 160 | 0% | 802 | 0 | Town |
| Lesterville | 5 | 114 | 113 | 0% | 564 | 0 | Town |
| Utica | 6 | 69 | 71 | 0% | 261 | 0 | Town |
Yankton is the largest city in Yankton County, with a population of 15,792.
Utica is the smallest city in Yankton County, with a population of 69.
There are 6 cities in Yankton County, South Dakota.