Williamson County, IL Property Taxes (2026)

Williamson County owners pay a median of $2,490 a year on a median home value of $145,600, an effective rate of 1.71%. That's the 63rd-highest rate of 102 Illinois counties with Census data, below the Illinois county median of 1.85%.

Updated October 2026 · Data: U.S. Census Bureau, American Community Survey 5-Year Estimates (2019–2023)

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Effective tax rate

1.71%

63rd highest of 102 in IL

Median annual bill

$2,490

~$208/month

Median home value

$145,600

Illinois county median

1.85%

Effective rate

What a protest could save you in Williamson County

Enter the market value from your appraisal notice. We apply Williamson County's 1.71% effective rate and a 10–15% reduction, the typical range for successful protests.

$
Est. annual tax
$2,490
Savings at 10–15% off
$249–$373
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Williamson County vs. Illinois vs. U.S. property tax rates

Williamson County1.71%
Illinois county median1.85%
U.S. county median0.84%

Key stat: Williamson County's effective property tax rate is 1.71%, vs. 1.85% for the median Illinois county and 0.84% for the median U.S. county. It ranks 63rd of 102 in Illinois. Effective rate = median tax bill ÷ median home value, so it already reflects typical exemptions. (Source: U.S. Census Bureau, American Community Survey 5-Year Estimates (2019–2023))

How to appeal your property taxes in Williamson County

  1. 1

    Review your assessment notice

    Check the assessed value from the Williamson County Assessor. Compare it to recent sales of similar homes nearby.

  2. 2

    File your appeal before the deadline

    The Williamson County deadline is 30 days after publication. Missing it means waiting until the next assessment year.

  3. 3

    Gather evidence

    Recent comparable sales, photos of condition issues, repair estimates or an independent appraisal.

  4. 4

    Present your case

    Submit evidence or attend a hearing with the County Assessor.

  5. 5

    Get your decision

    If you win, your assessed value and bill go down. On a $2,490 bill, 10–15% off is $249–$374 a year.

Want help with it?

TaxDrop builds your case from comparable sales data.

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Property tax exemptions in Illinois

Illinois homeowners may qualify for exemptions that reduce taxable value. Check with the Williamson County Assessor for amounts.

Homestead exemption

For your primary residence. Reduces the value used to calculate your bill.

Senior / over-65

Many states add an exemption or freeze for owners 65 and older.

Disability

For homeowners with qualifying disabilities, often similar to the over-65 benefit.

Veterans

Disabled veterans may get partial or full exemptions depending on rating.

Frequently Asked Questions

What is the property tax rate in Williamson County, Illinois?
The median effective property tax rate in Williamson County is 1.71%: a median annual bill of $2,490 on a median home value of $145,600. That's the 63rd-highest rate of 102 Illinois counties with Census data. Your own rate depends on which city, school district and special districts you're in. Source: U.S. Census Bureau, American Community Survey 5-Year Estimates (2019–2023).
How much are property taxes in Williamson County?
The median Williamson County property tax bill is $2,490 a year, about $208 a month, compared with a Illinois county median of $2,363.
What is the deadline to appeal property taxes in Williamson County?
The deadline to appeal in Williamson County is 30 days after publication. Missing it means waiting until the next assessment cycle.
Is Williamson County a high property tax area?
Williamson County's 1.71% effective rate is below the Illinois county median of 1.85% and above the U.S. county median of 0.84%. That's the 63rd-highest rate of 102 Illinois counties with Census data.
Can TaxDrop help lower my Williamson County property taxes?
TaxDrop analyzes your property against local comparable sales and helps you appeal your assessment.

Property taxes in nearby counties

Franklin County

Rate: 1.50%

Median bill: $1,316

Johnson County

Rate: 1.32%

Median bill: $1,952

Saline County

Rate: 1.56%

Median bill: $1,445

Union County

Rate: 1.41%

Median bill: $1,851

Jackson County

Rate: 1.91%

Median bill: $2,385

Pope County

Rate: 1.02%

Median bill: $1,687

Hamilton County

Rate: 1.35%

Median bill: $1,470

Perry County

Rate: 1.66%

Median bill: $1,744

← All 102 Illinois counties

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