4 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Allen | 1 | 1,052 | 477 | 4.16% | 324 | 3.24 | CDP |
| Martin | 2 | 919 | 936 | -0.33% | 1,641 | 0.56 | City |
| Allen township | 3 | 79 | 76 | 1.28% | 2 | 36.73 | Township |
| Martin township | 4 | 6 | 6 | 0% | 0.00 | 36.14 | Township |
Allen is the largest city in Bennett County, with a population of 1,052.
Martin township is the smallest city in Bennett County.
There are 4 cities in Bennett County, South Dakota.