12 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Sumter | 1 | 42,330 | 43,420 | -0.51% | 1,282 | 33.03 | City |
| Dalzell | 2 | 3,507 | 3,086 | 0.86% | 600 | 5.85 | CDP |
| Lakewood | 3 | 3,161 | 2,919 | 0.29% | 420 | 7.53 | CDP |
| Cherryvale | 4 | 2,930 | 3,298 | 1% | 1,620 | 1.81 | CDP |
| Wedgefield | 5 | 2,159 | 1,916 | 1.74% | 254 | 8.51 | CDP |
| Privateer | 6 | 2,152 | 2,487 | -0.6% | 263 | 8.17 | CDP |
| Cane Savannah | 7 | 1,638 | 1,052 | 2.12% | 451 | 3.63 | CDP |
| South Sumter | 8 | 1,352 | 2,249 | -4.99% | 579 | 2.34 | CDP |
| Mayesville | 9 | 539 | 551 | -0.37% | 526 | 1.02 | Town |
| Pinewood | 10 | 496 | 503 | -0.2% | 463 | 1.07 | Town |
| Rembert | 11 | 242 | 219 | -1.63% | 63 | 3.84 | CDP |
| Mulberry | 12 | 98 | 207 | -22.22% | 50 | 1.97 | CDP |
Sumter is the largest city in Sumter County, with a population of 42,330.
Mulberry is the smallest city in Sumter County.
There are 12 cities in Sumter County, South Carolina.