Home values, rents and more in Williamson County, IL
September 2026 figures from Zillow and the U.S. Census Bureau · updated 2026-11-07
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How Williamson County, IL compares
The typical home in Williamson County, IL is worth about $158,000, according to the Zillow Home Value Index for September 2026. Home values in Williamson County, IL are about the same as the typical value in the Marion metro area ($158,000) and 57% below the U.S. typical value ($366,000).
Over the past year, home values in Williamson County, IL rose 0.1%, compared with +0.1% in the Marion metro area and +1.2% nationally.
Typical rent is $988 a month (Zillow Observed Rent Index), 49% below the U.S. ($1,932). Rents rose 4.6% over the past year.
The median household income is $65,604, against $65,604 in the Marion metro area and $80,734 in the U.S. (Census Bureau, American Community Survey 2020–24).
About 67,225 people live in Williamson County, IL (Census Bureau estimate for July 2025).
Williamson County, IL has the 51st-lowest typical home value of the 102 counties in Illinois with Zillow figures.
Part of: Marion metro area · Illinois
More for Williamson County, IL in ProMap Plus
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- 5- and 10-year price changes
- Days on market and months of supply
- Price cuts and sale-to-list ratio
- Price-to-income and monthly cost to buy
- School test scores
- Flood, wildfire and natural hazard risk
- Property-tax rate
- Unemployment and job growth
- Building permits
- Mortgage delinquency
- 2024 presidential vote
- Age, education and household make-up
- Amenities and transit nearby
Nearby counties
Cities in Williamson County, IL
ZIP codes in Williamson County, IL
Sources
Home values: Zillow Home Value Index (ZHVI), all homes, middle tier, smoothed and seasonally adjusted, September 2026. Rents: Zillow Observed Rent Index (ZORI), seasonally adjusted. Population: Census population estimates (July 2025) for states, metros and counties; ACS 2020–24 for cities and ZIP codes. Income: U.S. Census Bureau, ACS 2020–24 5-year estimates. Boundaries: U.S. Census Bureau cartographic boundary files. Compiled by Home Economics.
"Typical" is Zillow's middle-tier value (homes between the 35th and 65th percentiles), not a median sale price. Changes are over the 12 months to September 2026.