Missouri · FIPS 29099 · County seat: Hillsboro
Jefferson County, MO GIS & Parcel Viewer
Jefferson County, Missouri parcel data lives on Jefferson County Property Viewer. Open it below in a new tab, then use the short steps on this page to find a property fast.
Open the Jefferson County parcel map ↗
Opens experience.arcgis.com in a new tab. We link out and never embed or copy parcel data.
Map and county facts
| Official map | Jefferson County Property Viewer |
|---|---|
| Type | County-run map |
| Website | experience.arcgis.com |
| Access | Free, no login (checked Oct 2026) |
| County seat | Hillsboro |
| Population | 231,230 (2023 Census Bureau estimate) |
| Land area | 656 sq mi |
| FIPS code | 29099 |
Who runs this map
This map is published by or for Jefferson County itself, so it reflects the local parcel layer rather than a third-party copy. Our October 2026 check found the map open to the public, with no account or payment needed.
How to use the Jefferson County viewer
- Open the link. This viewer is an ArcGIS Experience Builder app, so its layout is custom to the publisher.
- Look for a search box or search widget and type in a street address or parcel ID.
- Click a parcel to see its details in a pop-up or side panel.
- Check the toolbar for a layer list or basemap switcher if you want aerials or other layers.
Many parcel sites expect owner names last name first. If a full name finds nothing, try just the surname.
The county in brief
Jefferson County had an estimated 231,230 residents in 2023, according to the Census Bureau. With about 656 square miles of land, that works out to roughly 352 people per square mile. Among Missouri's 115 counties, it is the 7th largest by population. Hillsboro serves as the county seat.
Counties next to Jefferson County
Parcels close to the edge of Jefferson County can fall in the next county over. Neighboring counties:
- Franklin County
- St. Francois County
- St. Louis County
- Ste. Genevieve County (state list)
- Washington County (state list)
- Monroe County, IL (state list)
Related guides
Maps vs. surveys
The lines you see online are approximate. They're good for finding a lot and its parcel number, but a legal boundary question needs the recorded plat or a surveyor.