8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Faulkton | 1 | 818 | 830 | -0.24% | 808 | 1.01 | City |
| Cresbard | 2 | 104 | 101 | 0.97% | 251 | 0.41 | Town |
| Evergreen Colony | 3 | 93 | 245 | 8.14% | 93 | 1 | CDP |
| Brentwood Colony | 4 | 82 | 0 | 6.49% | 94 | 0.87 | CDP |
| Seneca | 5 | 23 | 22 | 0% | 55 | 0.42 | Town |
| Rockham | 6 | 21 | 20 | 0% | 42 | 0.50 | Town |
| Chelsea | 7 | 19 | 19 | 0% | 60 | 0.32 | Town |
| Onaka | 8 | 15 | 14 | 0% | 58 | 0.26 | Town |
Faulkton is the largest city in Faulk County, with a population of 818.
Onaka is the smallest city in Faulk County.
There are 8 cities in Faulk County, South Dakota.