40 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Clark | 1 | 1,165 | 1,149 | 0.26% | 861 | 1.35 | City |
| Mount Pleasant township | 2 | 286 | 256 | 3.25% | 8 | 35.88 | Township |
| Willow Lake | 3 | 261 | 260 | 0% | 702 | 0.37 | City |
| Lake township | 4 | 208 | 188 | 2.97% | 6 | 34.47 | Township |
| Pleasant township | 5 | 208 | 207 | 0% | 6 | 35.23 | Township |
| Collins township | 6 | 200 | 197 | 0% | 6 | 35.49 | Township |
| Fordham township | 7 | 147 | 146 | 0% | 4 | 35.52 | Township |
| Day township | 8 | 108 | 104 | 0% | 3 | 34.53 | Township |
| Clark township | 9 | 97 | 94 | 1.04% | 3 | 27.74 | Township |
| Washington township | 10 | 94 | 84 | 3.3% | 3 | 35.54 | Township |
| Elrod township | 11 | 89 | 85 | 0% | 2 | 36.13 | Township |
| Lincoln township | 12 | 89 | 85 | 0% | 3 | 35.02 | Township |
| Cottonwood township | 13 | 87 | 84 | 0% | 2 | 34.88 | Township |
| Rosedale township | 14 | 80 | 73 | 2.56% | 2 | 35.78 | Township |
| Clark Colony | 15 | 78 | 2 | 8.33% | 308 | 0.25 | CDP |
| Bradley | 16 | 66 | 63 | 1.54% | 269 | 0.24 | Town |
| Mayfield Colony | 17 | 66 | 2 | 6.45% | 256 | 0.26 | CDP |
| Darlington township | 18 | 65 | 58 | 3.17% | 2 | 35.78 | Township |
| Woodland township | 19 | 64 | 57 | 3.23% | 2 | 35.05 | Township |
| Raymond | 20 | 60 | 55 | 1.69% | 229 | 0.26 | Town |
| Vienna | 21 | 54 | 53 | 0% | 64 | 0.84 | Town |
| Garfield township | 22 | 54 | 51 | 0% | 2 | 35.93 | Township |
| Richland township | 23 | 52 | 49 | 0% | 1 | 35.87 | Township |
| Thorp township | 24 | 51 | 50 | 0% | 1 | 35.17 | Township |
| Willow Lake township | 25 | 49 | 47 | 0% | 1 | 35.49 | Township |
| Maydell township | 26 | 45 | 44 | 0% | 1 | 34.71 | Township |
| Raymond township | 27 | 44 | 42 | 0% | 1 | 35.60 | Township |
| Hague township | 28 | 43 | 42 | 0% | 1 | 35.83 | Township |
| Warren township | 29 | 42 | 41 | 0% | 1 | 35 | Township |
| Naples | 30 | 41 | 40 | 0% | 295 | 0.14 | Town |
| Foxton township | 31 | 41 | 40 | 0% | 1 | 35.91 | Township |
| Blaine township | 32 | 38 | 36 | 0% | 1 | 33.63 | Township |
| Logan township | 33 | 38 | 35 | 2.7% | 1 | 35.56 | Township |
| Merton township | 34 | 38 | 37 | 0% | 1 | 35.62 | Township |
| Garden City | 35 | 37 | 34 | 2.78% | 94 | 0.40 | Town |
| Spring Valley township | 36 | 34 | 32 | 0% | 1 | 35.10 | Township |
| Crocker | 37 | 26 | 25 | 8.33% | 7 | 3.63 | CDP |
| Ash township | 38 | 23 | 23 | 0% | 1 | 35.62 | Township |
| Clark township | 39 | 19 | 19 | 0% | 1 | 33.85 | Township |
| Clark township | 40 | 6 | 6 | 0% | 0.00 | 35.83 | Township |
Clark is the largest city in Clark County, with a population of 1,165.
Clark township is the smallest city in Clark County.
There are 40 cities in Clark County, South Dakota.