20 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Woonsocket | 1 | 659 | 631 | 0.92% | 841 | 0.78 | City |
| Butler township | 2 | 299 | 295 | -0.66% | 8 | 36.16 | Township |
| Letcher | 3 | 163 | 152 | 1.24% | 265 | 0.62 | Town |
| Woonsocket township | 4 | 147 | 144 | -0.68% | 4 | 35.49 | Township |
| Artesian | 5 | 137 | 131 | 0.74% | 247 | 0.55 | Town |
| Logan township | 6 | 137 | 134 | -0.72% | 4 | 35.98 | Township |
| Letcher township | 7 | 125 | 121 | 0% | 4 | 35.42 | Township |
| Jackson township | 8 | 118 | 110 | 1.72% | 3 | 34.40 | Township |
| Elliott township | 9 | 97 | 96 | -1.02% | 3 | 35.94 | Township |
| Twin Lake township | 10 | 96 | 93 | 0% | 3 | 35.70 | Township |
| Silver Creek township | 11 | 83 | 80 | 0% | 2 | 35.92 | Township |
| Floyd township | 12 | 72 | 65 | 2.86% | 2 | 34.39 | Township |
| Union township | 13 | 67 | 60 | 3.08% | 2 | 35.85 | Township |
| Forestburg | 14 | 52 | 78 | 6.12% | 98 | 0.53 | CDP |
| Ravenna township | 15 | 44 | 43 | 0% | 1 | 35.47 | Township |
| Warren township | 16 | 44 | 44 | -2.22% | 1 | 35.24 | Township |
| Diana township | 17 | 43 | 42 | 0% | 1 | 35.32 | Township |
| Afton township | 18 | 30 | 32 | -3.23% | 1 | 34.48 | Township |
| Benedict township | 19 | 26 | 28 | -3.7% | 1 | 35.87 | Township |
| Oneida township | 20 | 25 | 25 | 0% | 1 | 35.66 | Township |
Woonsocket is the largest city in Sanborn County, with a population of 659.
Oneida township is the smallest city in Sanborn County.
There are 20 cities in Sanborn County, South Dakota.