Sioux City, IA ZIP Codes
Sioux City, Iowa has 9 ZIP codes: 8 for street addresses (, , , , , and 2 more) and 1 for PO boxes.
Your street decides which one you use.
Which Sioux City ZIP code is my address in?
Street ranges from the Census Bureau, 2026. PO box and organization ZIP codes are not found by street. A new street may be missing: address not found?
Sioux City ZIP code map
Tap or point to an area to see its ZIP code.Full-size map
51102 has no area on the map: it is a PO box or single-organization ZIP code. Dashed line: Sioux City city limits.
Map: Census Bureau ZIP Code Tabulation Areas (2020) and place limits (2024).
All Sioux City ZIP codes by type
| ZIP | Type and post office or station |
|---|---|
| 51101 | street delivery Sioux City Sorting and Delivery Center |
| 51102 | PO boxes at the Sioux City Sorting and Delivery Center post office Sioux City Sorting and Delivery Center |
| 51103 | street delivery Sioux City Sorting and Delivery Center |
| 51104 | street delivery Sioux City Sorting and Delivery Center |
| 51105 | street delivery Sioux City Sorting and Delivery Center |
| 51106 | street delivery Sioux City Sorting and Delivery Center |
| 51108 | street delivery Sioux City Sorting and Delivery Center |
| 51109 | street delivery Sioux City Sorting and Delivery Center |
| 51111 | street delivery Sioux City Sorting and Delivery Center |
ZIP codes from nearby towns that reach into Sioux City
- 51054, mailing town Sergeant Bluff, covers 2 percent of Sioux City
Why your mail may say Sioux City when you live outside it
A letter addressed to Sioux City can go to a home outside the city limits, because ZIP areas follow delivery routes, not town lines.
The reverse happens too: parts of Sioux City use 51054, which mails under a neighboring town's name.
A ZIP code does not set your city, school district or tax. Woodbury County property records show which city you are in.
Sioux City ZIP code questions
What is the main ZIP code for Sioux City?
51101, the ZIP code of the main Sioux City Sorting and Delivery Center post office at 214 Jackson St.
Which Sioux City ZIP codes are for PO boxes only?
51102. Mail to it goes to boxes at the post office, not to street addresses.
What county is Sioux City in?
Woodbury County.
ZIP codes for towns near Sioux City
More towns near Sioux City: Urbandale, Grand Island, West Des Moines, Ankeny, Des Moines, Mankato, Kearney, Cedar Falls, Waterloo.
Sources and last checked
USPS ZIP Locale Detail (October 1, 2026), GeoNames (CC BY 4.0), U.S. Census Bureau, HUD-USPS crosswalk.
Checked October 20, 2026. Sources · How we build our lists · Corrections