ZIP codes in Hamilton County
27 ZIPs touch Hamilton County, Indiana. The blue dashed line is the county border; orange ZIPs reach into it.
27
ZIP codes
13
cross the county line
567,844
people in these ZIPs
92
counties in IN
Most people
Hamilton County ZIP list
More counties in Indiana
- Fountain County10
- Franklin County15
- Fulton County19
- Gibson County17
- Grant County15
- Greene County18
- Hancock County17
- Harrison County16
- Hendricks County19
- Henry County23
- Howard County15
- Huntington County9
Questions people actually ask
How many ZIP codes are in Hamilton County, Indiana?
27 ZIP codes reach into Hamilton County, including 4 PO Box or single-address ZIPs placed by the town they serve. 13 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Hamilton County has the most people?
46032 (Carmel) has about 51,515 residents, the most of any ZIP touching Hamilton County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Hamilton 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 Hamilton 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