Missouri · FIPS 29189 · County seat: Clayton
St. Louis County, MO GIS & Parcel Viewer
St. Louis County, Missouri parcel data lives on Property Lookup for St. Louis County. Open it below in a new tab, then use the short steps on this page to find a property fast.
Open the St. Louis County parcel map ↗
Opens experience.arcgis.com in a new tab. We link out and never embed or copy parcel data.
St. Louis County at a glance
| Official map | Property Lookup for St. Louis County |
|---|---|
| Type | County-run map |
| Website | experience.arcgis.com |
| Access | Free, no login (checked Oct 2026) |
| County seat | Clayton |
| Population | 987,059 (2023 Census Bureau estimate) |
| Land area | 508 sq mi |
| FIPS code | 29189 |
About the official source
It is a county-level map: St. Louis County or the company it hires keeps the parcel layer up to date. Our October 2026 check found the map open to the public, with no account or payment needed.
How to use the St. Louis County viewer
- Press the button above; an ArcGIS Experience Builder app opens in a new tab. Accept any splash or disclaimer screen.
- Search by address or parcel ID, or pan to the area.
- Select a parcel to view the information the publisher makes available.
- Explore the app's panels for layers, legends or printing.
If an address search comes up empty, try the parcel number from a tax bill or deed instead, or click the lot on the map.
The county in brief
The U.S. Census Bureau estimated St. Louis County's population at 987,059 in 2023, spread over about 508 square miles of land, or roughly 1,943 people per square mile. That makes it the most populous of Missouri's 115 counties. The county seat is Clayton.
Counties next to St. Louis County
Parcels close to the edge of St. Louis County can fall in the next county over. Neighboring counties:
- Franklin County
- Jefferson County
- St. Charles County
- St. Louis City (state list)
- Madison County, IL
- Monroe County, IL (state list)
- St. Clair County, IL (state list)
Before you rely on the lines
Keep in mind that a GIS parcel layer is a tax map, not a survey. For exact boundaries, look at the recorded deed and plat or hire a licensed land surveyor.