4 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 29812 | Barnwell | 10,965 |
| 29853 | Williston | 6,011 |
| 29817 | Blackville | 4,230 |
| 29826 | Elko | 194 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 4 ZCTAs in Barnwell County, South Carolina (US Census).