12 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Walterboro | 1 | 5,484 | 5,521 | -0.07% | 801 | 7 | City |
| Walterboro | 2 | 5,484 | 5,503 | -0.07% | 801 | 7 | City |
| Cottageville | 3 | 724 | 701 | 0.56% | 212 | 3 | Town |
| Cottageville | 4 | 724 | 701 | 0.56% | 212 | 3 | Town |
| Jacksonboro | 5 | 218 | 200 | -7.23% | 15 | 14 | CDP |
| Smoaks | 6 | 97 | 99 | -1.02% | 60 | 2 | Town |
| Smoaks | 7 | 97 | 99 | -1.02% | 60 | 2 | Town |
| Williams | 8 | 97 | 97 | 0% | 115 | 1 | Town |
| Williams | 9 | 97 | 97 | 0% | 115 | 1 | Town |
| Lodge | 10 | 82 | 82 | 0% | 26 | 3 | Town |
| Lodge | 11 | 82 | 82 | 0% | 26 | 3 | Town |
| Islandton | 12 | 50 | 49 | 6.38% | 18 | 3 | CDP |
Walterboro is the largest city in Colleton County, with a population of 5,484.
Islandton is the smallest city in Colleton County, with a population of 50.
There are 12 cities in Colleton County, South Carolina.