| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Bennettsville | 1 | 7,477 | 7,957 | -1.16% | 1,210 | 6 | City |
| McColl | 2 | 1,953 | 2,061 | -1.06% | 1,860 | 1 | Town |
| Clio | 3 | 571 | 603 | -1.04% | 667 | 1 | Town |
| Blenheim | 4 | 105 | 113 | -1.87% | 161 | 1 | Town |
| Tatum | 5 | 69 | 74 | -1.43% | 76 | 1 | Town |
Bennettsville is the largest city in Marlboro County, with a population of 7,477.
Tatum is the smallest city in Marlboro County, with a population of 69.
There are 5 cities in Marlboro County, South Carolina.