4 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Highmore | 1 | 610 | 674 | -2.09% | 324 | 1.89 | City |
| Stephan | 2 | 54 | 106 | 8% | 196 | 0.28 | CDP |
| Valley | 3 | 10 | 11 | 0% | 0.00 | 36.04 | Township |
| William Hamilton | 4 | 6 | 6 | 0% | 0.00 | 35.69 | Township |
Highmore is the largest city in Hyde County, with a population of 610.
William Hamilton is the smallest city in Hyde County, with a population of 6.
There are 4 cities in Hyde County, South Dakota.