| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Columbia | 1 | 149,103 | 135,860 | 1.41% | 1,070 | 139 | City |
| Irmo | 2 | 12,353 | 11,511 | 1.22% | 1,809 | 7 | Town |
| Forest Acres | 3 | 10,348 | 10,629 | -0.4% | 2,238 | 5 | City |
| Blythewood | 4 | 7,700 | 4,852 | 6.46% | 724 | 11 | Town |
| Arcadia Lakes | 5 | 849 | 869 | -0.35% | 1,524 | 1 | Town |
| Eastover | 6 | 707 | 687 | 0.43% | 582 | 1 | Town |
Columbia is the largest city in Richland County, with a population of 149,103.
Eastover is the smallest city in Richland County, with a population of 707.
There are 6 cities in Richland County, South Carolina.