8 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 71730 | El Dorado | 29,760 |
| 71762 | Smackover | 2,929 |
| 71749 | Junction City | 2,787 |
| 71765 | Strong | 1,742 |
| 71747 | Huttig | 655 |
| 71759 | Norphlet | 243 |
| 71758 | Mount Holly | 150 |
| 71724 | Calion | 147 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 8 ZCTAs in Union County, Arkansas (US Census).