Postal reference / United States
51101Sioux City, Iowa
ZIP code 51101 is a United States postal code for Sioux City, Iowa. Its county association is Woodbury County. The map reference point is at 42.4972, -96.4029.
- State / territory
- Iowa
- Recorded place name
- Sioux City
- County association
- Woodbury
- Estimated coordinate
- 42.4972, -96.4029
View on OpenStreetMap - ZIP prefix
- 511 · 9 ZIP codes share it
- Data source
- GeoNames postal reference, snapshot September 26, 2026
GeoNames reference data. County associations may not include every intersecting county, place names are postal names rather than legal boundaries, and coordinates are approximate. This is not address validation.
Area
- Land area
- 1.203 sq mi (2023 Census Gazetteer)
Figures are for the ZIP Code Tabulation Area (ZCTA) that most closely matches this ZIP code, not an exact match to USPS delivery boundaries. Source: U.S. Census Bureau, 2023 Gazetteer + 2023 ACS 5-Year Estimates, retrieved 2026-09-27. How to read this data.
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Browse the other 1,054 ZIP codes recorded for Iowa, sorted by code with place and county.
Iowa directoryOther ZIP codes in Sioux City, IA
Sioux City has 9 ZIP codes in the reference dataset.
Nearby ZIP code reference points
| ZIP code | Place | State | County association | Miles |
|---|---|---|---|---|
| 51105 | Sioux City | IA | Woodbury | 1.1 |
| 51103 | Sioux City | IA | Woodbury | 1.5 |
| 51104 | Sioux City | IA | Woodbury | 2.0 |
| 68776 | South Sioux City | NE | Dakota | 2.3 |
| 51106 | Sioux City | IA | Woodbury | 3.3 |
| 51108 | Sioux City | IA | Woodbury | 4.0 |
| 51109 | Sioux City | IA | Woodbury | 4.2 |
| 57049 | North Sioux City | SD | Union | 5.7 |
Straight-line distance between reference points. Nearby points do not prove that ZIP areas touch.
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