LandBrief

Williamson County

Parcel & Property Data

50,672Total Parcels
—Avg. Market Value
261,016Total Acres

About This Data

LandBrief holds 50,672 parcel records for Williamson County, sourced from county records. Each includes the parcel boundary, and — where the county publishes them — owner, situs address, acreage, assessed values and legal description.

Data from the Williamson County assessor roll dated July 2025, loaded August 2026. See data sources for every county’s vintage.

Explore Williamson County

Williamson County by the Numbers

Median parcel size
0.37 acres
measured from mapped boundaries
90th-percentile parcel
14.3 acres
County land area
268,935 acres
U.S. Census measurement
Communities
27
21.6% of parcels outside any incorporated place

Who Owns Williamson County?

Share of the county’s 50,672 parcels by the kind of owner on record. Classified from owner names, so the boundaries are approximate; an entity the rules cannot place counts as an individual.

Owner typeShare of parcels
Individuals76.7%
Companies & organizations11.1%
Trusts & estates7.2%
Government3.5%
Other / unclassified1.6%

The largest owner on record is CITY OF MARION with 422 parcels — see the full landowner leaderboard.

Parcel Records (~50,672 total)

per page
Parcel IDOwnerAddressCityAcreage
02-07-100-001KIRCHNER FARMS LLC—Unincorporated170.82
01-14-200-001FUNK'S FARMSCARTERVILLE IL; 62918Unincorporated163.60
11-24-200-004SATTERFIELD LANDON & SALLYCREAL SPRINGS, IL.; 62922Unincorporated162.01
08-08-400-001LAMPLEY JAMES STEVENPITTSBURG, IL.; 62974Unincorporated161.95
12-18-100-001DUNTEMAN JAMES W TRUSTEE—Unincorporated161.62
01-06-100-001SOUTHERN ILLINOIS HARVEST LLC—Unincorporated160.00
01-06-300-001SOUTHERN ILLINOIS HARVEST LLC—Unincorporated160.00
01-12-300-001BASLER MARIE RONALD & RICKIEHERRIN IL; 62948Unincorporated160.00
05-25-100-001UNITED STATES DEPT OF INTERIOR8144 N WOLF CREEK RD; CARTERVILLE IL; 62918Unincorporated160.00
05-24-300-001UNITED STATES DEPT OF INTERIOR8788 N WOLF CREEK RD; CARTERVILLE IL; 62918Unincorporated160.00
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Download Williamson County parcel data

All 50,672 parcels in Williamson County as a single file — free, no account needed. Shapefile, GeoJSON, GeoPackage, CSV and Parquet.

Get Williamson County on FreeParcelData →

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Frequently Asked Questions

How many parcels are in Williamson County?

The Williamson County assessor roll on file records 50,672 parcels across 27 communities, with 21.6% lying outside any incorporated place.

Who owns the most land in Williamson County?

CITY OF MARION holds 422 parcels, the most of any owner on record — the largest-landowners leaderboard ranks the top 25.

What is the typical parcel size in Williamson County?

Measured from mapped boundaries, the median parcel is 0.37 acres, and nine parcels in ten are under 14.3 acres. Boundary-measured area closely tracks deeded acreage but is not the deed.

How much of Williamson County is government-owned?

Government entities — federal, state, and local — hold 3.5% of the county’s parcels, classified from owner names on the roll.

How current is this data?

It comes from the Williamson County assessor roll dated July 2025. Counties deliver on their own schedules; the methodology page explains how records are processed and the data sources page tracks every county’s vintage.

Browse by City (27)

50,672 parcels across 27 communities in Williamson County.