13 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 51250 | Sioux Center | 9,887 |
| 51041 | Orange City | 7,173 |
| 51201 | Sheldon | 6,226 |
| 51247 | Rock Valley | 5,028 |
| 51023 | Hawarden | 3,437 |
| 51239 | Hull | 2,947 |
| 51003 | Alton | 1,815 |
| 51238 | Hospers | 1,483 |
| 51027 | Ireton | 1,443 |
| 51234 | Boyden | 1,090 |
| 51036 | Maurice | 483 |
| 51244 | Matlock | 140 |
| 51011 | Chatsworth | 80 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 13 ZCTAs in Sioux County, Iowa (US Census).