20 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Columbia | 1 | 146,563 | 136,195 | 1.44% | 1,060 | 138.26 | City |
| Lexington | 2 | 25,766 | 23,653 | 1.67% | 2,153 | 11.97 | Town |
| St. Andrews | 3 | 22,263 | 21,355 | 0.53% | 3,624 | 6.14 | CDP |
| West Columbia | 4 | 18,847 | 17,519 | 1.43% | 2,011 | 9.37 | City |
| Seven Oaks | 5 | 15,997 | 16,743 | 0.36% | 2,091 | 7.65 | CDP |
| Cayce | 6 | 13,594 | 13,758 | -0.24% | 805 | 16.88 | City |
| Oak Grove | 7 | 11,658 | 12,040 | 0.79% | 1,538 | 7.58 | CDP |
| Red Bank | 8 | 10,776 | 9,971 | 0.73% | 860 | 12.54 | CDP |
| White Knoll | 9 | 8,981 | 7,476 | 7.15% | 1,468 | 6.12 | CDP |
| Lake Murray Richland | 10 | 7,272 | 6,672 | 1.68% | 1,311 | 5.55 | CDP |
| Springdale | 11 | 2,707 | 2,739 | -0.22% | 1,001 | 2.70 | Town |
| South Congaree | 12 | 2,392 | 2,374 | 0.17% | 727 | 3.29 | Town |
| Chapin | 13 | 1,968 | 1,817 | 1.55% | 994 | 1.98 | Town |
| Gaston | 14 | 1,646 | 1,611 | 0.43% | 310 | 5.32 | Town |
| Edmund | 15 | 1,436 | 930 | 7.16% | 210 | 6.83 | CDP |
| Swansea | 16 | 782 | 726 | 1.43% | 375 | 2.09 | Town |
| Fairview Crossroads | 17 | 735 | 665 | 7.14% | 129 | 5.71 | CDP |
| Gilbert | 18 | 632 | 577 | 1.77% | 233 | 2.71 | Town |
| Pelion | 19 | 623 | 627 | -0.16% | 169 | 3.68 | Town |
| Summit | 20 | 467 | 422 | 1.97% | 314 | 1.49 | Town |
Columbia is the largest city in Lexington County, with a population of 146,563.
Summit is the smallest city in Lexington County.
There are 20 cities in Lexington County, South Carolina.