ZIP codes in Dubuque County
22 ZIPs touch Dubuque County, Iowa. The blue dashed line is the county border; orange ZIPs reach into it.
22
ZIP codes
12
cross the county line
112,668
people in these ZIPs
99
counties in IA
Most people
Dubuque County ZIP list
More counties in Iowa
- Dallas County25
- Davis County10
- Decatur County11
- Delaware County17
- Des Moines County12
- Dickinson County10
- Emmet County7
- Fayette County24
- Floyd County13
- Franklin County19
- Fremont County11
- Greene County14
Questions people actually ask
How many ZIP codes are in Dubuque County, Iowa?
22 ZIP codes reach into Dubuque County, including 2 PO Box or single-address ZIPs placed by the town they serve. 12 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Dubuque County has the most people?
52001 (Dubuque) has about 43,101 residents, the most of any ZIP touching Dubuque County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Dubuque County and another county?
Yes. ZIP codes follow mail routes, not county lines. Rows marked with a percentage show how much of that ZIP’s land is in Dubuque County. For one address, pin the exact spot on the ZIP finder to see its county.
Where does this list come from?
ZIP areas and their county overlaps come from the Census Bureau’s 2020 ZIP Code Tabulation Area to county relationship file. PO Box ZIPs have no area, so each is placed in the county of the ZIP area nearest the town it serves.
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Updated 2026-11-10 · Where the data comes from