19 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Woonsocket | 1 | 653 | 631 | 0.62% | 833 | 1 | City |
| Butler | 2 | 307 | 295 | 0.33% | 8 | 36 | Township |
| Letcher | 3 | 162 | 153 | 1.25% | 263 | 1 | Town |
| Woonsocket | 4 | 146 | 144 | -0.68% | 4 | 35 | Township |
| Logan | 5 | 141 | 139 | -0.7% | 4 | 36 | Township |
| Artesian | 6 | 137 | 130 | 0.74% | 247 | 1 | Town |
| Letcher | 7 | 122 | 121 | -0.81% | 3 | 35 | Township |
| Jackson | 8 | 111 | 110 | -0.89% | 3 | 34 | Township |
| Twin Lake | 9 | 93 | 93 | -1.06% | 3 | 36 | Township |
| Elliott | 10 | 91 | 91 | -1.09% | 3 | 36 | Township |
| Silver Creek | 11 | 82 | 82 | -1.2% | 2 | 36 | Township |
| Floyd | 12 | 67 | 67 | -1.47% | 2 | 34 | Township |
| Union | 13 | 55 | 55 | -1.79% | 2 | 36 | Township |
| Warren | 14 | 47 | 45 | 0% | 1 | 35 | Township |
| Diana | 15 | 45 | 47 | -2.17% | 1 | 35 | Township |
| Ravenna | 16 | 37 | 39 | -2.63% | 1 | 35 | Township |
| Afton | 17 | 32 | 32 | 0% | 1 | 34 | Township |
| Benedict | 18 | 31 | 31 | 0% | 1 | 36 | Township |
| Oneida | 19 | 25 | 25 | 0% | 1 | 36 | Township |
Woonsocket is the largest city in Sanborn County, with a population of 653.
Oneida is the smallest city in Sanborn County, with a population of 25.
There are 19 cities in Sanborn County, South Dakota.