20 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Woonsocket | 1 | 649 | 631 | 0.46% | 828 | 1 | City |
| Butler | 2 | 306 | 295 | 0.33% | 8 | 36 | Township |
| Letcher | 3 | 160 | 153 | 0.63% | 260 | 1 | Town |
| Woonsocket | 4 | 147 | 144 | -0.68% | 4 | 35 | Township |
| Logan | 5 | 142 | 139 | -0.7% | 4 | 36 | Township |
| Artesian | 6 | 136 | 130 | 0.74% | 245 | 1 | Town |
| Letcher | 7 | 123 | 121 | -0.81% | 3 | 35 | Township |
| Jackson | 8 | 112 | 110 | -0.88% | 3 | 34 | Township |
| Twin Lake | 9 | 94 | 93 | -1.05% | 3 | 36 | Township |
| Elliott | 10 | 92 | 91 | -1.08% | 3 | 36 | Township |
| Silver Creek | 11 | 83 | 82 | -1.19% | 2 | 36 | Township |
| Floyd | 12 | 68 | 67 | -1.45% | 2 | 34 | Township |
| Union | 13 | 56 | 55 | -1.75% | 2 | 36 | Township |
| Forestburg | 14 | 52 | 78 | 6.12% | 98 | 1 | CDP |
| Warren | 15 | 47 | 45 | 0% | 1 | 35 | Township |
| Diana | 16 | 46 | 47 | -2.13% | 1 | 35 | Township |
| Ravenna | 17 | 38 | 39 | -2.56% | 1 | 35 | Township |
| Afton | 18 | 32 | 32 | 0% | 1 | 34 | Township |
| Benedict | 19 | 31 | 31 | 0% | 1 | 36 | Township |
| Oneida | 20 | 25 | 25 | 0% | 1 | 36 | Township |
Woonsocket is the largest city in Sanborn County, with a population of 649.
Oneida is the smallest city in Sanborn County, with a population of 25.
There are 20 cities in Sanborn County, South Dakota.