4 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 29812 | Barnwell | 11,132 |
| 29853 | Williston | 5,944 |
| 29817 | Blackville | 4,139 |
| 29826 | Elko | 241 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 4 ZCTAs in Barnwell County, South Carolina (US Census).