Illinois · FIPS 17027 · County seat: Carlyle
Clinton County, IL GIS & Parcel Viewer
Clinton County, Illinois parcel data lives on Clinton County Assessor Portico map. Open it below in a new tab, then use the short steps on this page to find a property fast.
Open the Clinton County parcel map ↗
Opens portico.sidwellco.com in a new tab. We link out and never embed or copy parcel data.
Quick facts
| Official map | Clinton County Assessor Portico map |
|---|---|
| Type | County-run map |
| Website | portico.sidwellco.com |
| Access | Free, no login (checked Oct 2026) |
| County seat | Carlyle |
| Population | 36,785 (2023 Census Bureau estimate) |
| Land area | 474 sq mi |
| FIPS code | 17027 |
Where the parcel data comes from
This map is published by or for Clinton County itself, so it reflects the local parcel layer rather than a third-party copy. When we tested the link in October 2026 it opened with no login and no fee.
Finding a property on this map
- Open the official link; the viewer runs on Esri's ArcGIS platform.
- Find the search control and type in a street address or parcel ID, or zoom in by hand.
- Click a parcel to see the attributes the publisher shares.
- Use any layer or basemap tools to add aerial imagery or other map layers.
Have a tax bill handy? The parcel or account number on it is usually the fastest way to search.
The county in brief
Clinton County had an estimated 36,785 residents in 2023, according to the Census Bureau. With about 474 square miles of land, that works out to roughly 78 people per square mile. By population it ranks 36th of 102 counties in Illinois. Carlyle serves as the county seat.
Counties next to Clinton County
Parcels close to the edge of Clinton County can fall in the next county over. Neighboring counties:
Maps vs. surveys
Treat the map as a guide, not a boundary survey: parcel outlines are often shifted a bit from the real corners. A licensed surveyor settles exact lines.