20 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 51106 | Sioux City | 28,381 |
| 51104 | Sioux City | 22,792 |
| 51103 | Sioux City | 17,145 |
| 51105 | Sioux City | 10,726 |
| 51054 | Sergeant Bluff | 5,596 |
| 51039 | Moville | 2,831 |
| 51030 | Lawton | 1,630 |
| 51055 | Sloan | 1,189 |
| 51016 | Correctionville | 1,095 |
| 51101 | Sioux City | 1,077 |
| 51052 | Salix | 1,054 |
| 51026 | Hornick | 1,050 |
| 51004 | Anthon | 853 |
| 51007 | Bronson | 581 |
| 51048 | Pierson | 465 |
| 51019 | Danbury | 441 |
| 51056 | Smithland | 332 |
| 51044 | Oto | 173 |
| 51015 | Climbing Hill | 70 |
| 51111 | Sioux City | 48 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 20 ZCTAs in Woodbury County, Iowa (US Census).