Jefferson County, Missouri
Jefferson County is a county in Missouri. Its county FIPS code is 29099. Use the boundary map and neighboring areas below to check the jurisdiction you need.
- Official code
- 29099
- Representative coordinates
- 38.257629, -90.543680
- County type
- County
- County seat or government
- Hillsboro
- Resident population, July 2025
- 233,132
- Land area
- 1,699.141 km²
- Water area
- 20.248 km²
- State
- Missouri
The representative point identifies this area. It is not a street address or a boundary survey.
Time zones in Jefferson County
| Time zone | Local time and UTC offset | Next clock change |
|---|---|---|
| America/Chicago | UTC-06:00 in January; UTC-05:00 in July. Enable JavaScript for the live clock. | Enable JavaScript for upcoming changes. |
Listed zones overlap the mapped area. A point lookup can distinguish sides of a boundary. Your device’s zone may differ.
Census ZIP areas
63010 · 63012 · 63015 · 63016 · 63019 · 63020 · 63023 · 63025 · 63026 · 63028 · 63030 · 63041 · 63047 · 63048 · 63049 · 63050 · 63051 · 63052 · 63053 · 63069 · 63070 · 63072 · 63087 · 63128 · 63627 · 63628
These statistical areas overlap the boundary. They are not delivery assignments; confirm mailing details with USPS ZIP Code Lookup.
Official county information
Use the US government local-office directory ↗ to find the office responsible for your address. A county website has not been confidently matched here. A geographic lookup cannot determine eligibility, tax liability or a court obligation.
Cities, towns and communities
These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.
- Arnold city, MO
- Barnhart CDP, MO
- Briarwood Estates CDP, MO
- Byrnes Mill city, MO
- Cedar Hill CDP, MO
- Cedar Hill Lakes village, MO
- Crystal City city, MO
- De Soto city, MO
- Eureka city, MO
- Festus city, MO
- Herculaneum city, MO
- High Ridge CDP, MO
- Hillsboro city, MO
- Horine CDP, MO
- Imperial CDP, MO
- Kimmswick city, MO
- LaBarque Creek CDP, MO
- Lake Tekakwitha village, MO
- Murphy CDP, MO
- Olympian Village city, MO
- Parkdale village, MO
- Peaceful Village village, MO
- Pevely city, MO
- Raintree Plantation CDP, MO
- Scotsdale town, MO
- Summer Set CDP, MO
Areas sharing the mapped boundary
These areas touch this mapped boundary.
Before using this answer on a form
Use a precise point for address-level questions. A device accuracy circle can cross a boundary; confirm tax, voting or jury details with the responsible office.
Find the county at your current point, check its ZIP area, or find its physical time zone.