13 ZIP Codes
| Zip Code | City | Population ↓ |
|---|---|---|
| 51250 | Sioux Center | 9,970 |
| 51041 | Orange City | 7,324 |
| 51201 | Sheldon | 6,430 |
| 51247 | Rock Valley | 5,094 |
| 51023 | Hawarden | 3,473 |
| 51239 | Hull | 2,876 |
| 51003 | Alton | 1,938 |
| 51238 | Hospers | 1,502 |
| 51027 | Ireton | 1,280 |
| 51234 | Boyden | 1,172 |
| 51036 | Maurice | 445 |
| 51244 | Matlock | 144 |
| 51011 | Chatsworth | 54 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 13 ZCTAs in Sioux County, Iowa (US Census).