Maryland · FIPS 24037 · County seat: Leonardtown
St. Mary's County, MD GIS & Parcel Viewer
Here is the direct link to the statewide parcel map covering St. Mary's County, MD: Maryland FINDER Online (MD Dept. of Planning). Below you'll find basic facts about the county, steps for using the viewer, and nearby counties.
Open the St. Mary's County statewide map ↗
Opens experience.arcgis.com in a new tab. We link out and never embed or copy parcel data.
St. Mary's County at a glance
| Official map | Maryland FINDER Online (MD Dept. of Planning) |
|---|---|
| Type | Statewide map (covers all of Maryland) |
| Website | experience.arcgis.com |
| Access | Free, no login (checked Oct 2026) |
| County seat | Leonardtown |
| Population | 115,281 (2023 Census Bureau estimate) |
| Land area | 359 sq mi |
| FIPS code | 24037 |
Who runs this map
This is a statewide map, not a county site. Maryland FINDER Online (MD Dept. of Planning) covers parcels across Maryland, and St. Mary's County is one part of it. Statewide parcel layers are usually stitched together from county files, so the newest splits or sales may show up on the county's own records first. As of our October 2026 test, anyone could open it without signing in or paying.
How to use the St. Mary's County viewer
- Press the button to load the statewide viewer, then move the map to St. Mary's County.
- Use the viewer's search tool to find an address or parcel, if it has one.
- Click a lot to read its details.
- For deeds, taxes or official copies, take the parcel number to the county's own offices.
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.
St. Mary's County by the numbers
St. Mary's County had an estimated 115,281 residents in 2023, according to the Census Bureau. With about 359 square miles of land, that works out to roughly 321 people per square mile. Among Maryland's 24 counties, it is the 12th largest by population. Another 406 square miles of water fall within its lines, according to Census mapping. Leonardtown serves as the county seat.
Nearby parcel maps
Parcels close to the edge of St. Mary's County can fall in the next county over. Neighboring counties:
- Calvert County
- Charles County
- Dorchester County
- Somerset County
- Northumberland County, VA
- Westmoreland County, VA
A note on accuracy
Online parcel lines are drawn for tax and planning use. They can be off by several feet, so use a recorded plat or a licensed surveyor for fences, setbacks or a sale.