Founded in 1919, Allendale County is one of 46 counties in the state of South Carolina. Historically, Allendale County was formed from Barnwell and Hampton. The city of Allendale is the county seat. With FIPS code of 5, Allendale County has a population of 7,858 and area of 413 square miles (1,070 km2).
List of all cities in Allendale County, SC alphabetically
| City/Town | Postal Code | Area Code |
| Allendale, SC | 29810 | 803 |
| Barton, SC | 29827 | 803 |
| Fairfax, SC | 29827 | 803 |
| Martin, SC | 29836 | 803 |
| Seigling, SC | 29810 | 803 |
| Sycamore, SC | 29846 | 803 |
| Ulmer, SC | 29849 | 803 |