7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hartsville | 1 | 7,378 | 7,430 | -0.14% | 1,232 | 5.99 | City |
| Darlington | 2 | 5,967 | 6,192 | -0.75% | 1,266 | 4.71 | City |
| Dovesville | 3 | 1,185 | 1,101 | 7.14% | 169 | 7.01 | CDP |
| Quinby | 4 | 899 | 914 | -0.33% | 688 | 1.31 | Town |
| Lamar | 5 | 834 | 856 | -0.48% | 688 | 1.21 | Town |
| Society Hill | 6 | 426 | 435 | -0.47% | 198 | 2.15 | Town |
| Lydia | 7 | 123 | 419 | -22.15% | 47 | 2.64 | CDP |
Hartsville is the largest city in Darlington County, with a population of 7,378.
Lydia is the smallest city in Darlington County.
There are 7 cities in Darlington County, South Carolina.