Williamson County, IL property tax
Census ACS 2023 5-year estimates · updated 2026-09-20
The median effective property tax rate in Williamson County is 1.71%, below the Illinois median of 2.07% and above the national median of 0.98%. The median homeowner pays $2,490 a year on a home worth $145,600.
- Effective rate
- 1.71%
- Median annual bill
- $2,490
- Median home value
- $145,600
- Rank in Illinois
- 63of 102
Median annual bill divided by median home value, Census ACS 2023 5-year estimates.
Estimated annual bill by home value
| Home value | Estimated bill | Per month |
|---|---|---|
| $200,000 | $3,420 | $285 |
| $300,000 | $5,130 | $428 |
| $400,000 | $6,840 | $570 |
| $500,000 | $8,550 | $713 |
| $750,000 | $12,825 | $1,069 |
| $1,000,000 | $17,100 | $1,425 |
Property tax rates by city in Williamson County, 2024
For tax year 2024, billed in 2025, the average residential tax at each city's rate in Williamson County ran from $1,566 in Colp to $2,315 in Creal Springs. Across all property in the county, the average tax rate was 7.26 per $100 of equalized assessed value, down from 7.58 in 2023.
Illinois rates apply to taxable value, not market value, so a rate of 7 means $7 per $100 of taxable value. The effective rate column turns each tax into a share of market value, which is the figure to compare between cities.
| City | Township or road district | Average tax 2024 | Average tax 2023 | Effective rate | Aggregate rate | Average home value |
|---|---|---|---|---|---|---|
| Creal Springs | Williamson County Unit Road Districts | $2,315 | 2.18% | 9.3659 | $106,295 | |
| Herrin | Williamson County Unit Road Districts | $1,970 | 1.85% | 7.9691 | $106,295 | |
| Johnston City | Williamson County Unit Road Districts | $1,938 | 1.82% | 7.8420 | $106,295 | |
| Pittsburg | Williamson County Unit Road Districts | $1,935 | 1.82% | 7.8269 | $106,295 | |
| Cambria | Williamson County Unit Road Districts | $1,917 | 1.80% | 7.7567 | $106,295 | |
| Carterville | Williamson County Unit Road Districts | $1,908 | 1.79% | 7.7174 | $106,295 | |
| Energy | Williamson County Unit Road Districts | $1,874 | 1.76% | 7.5801 | $106,295 | |
| Marion | Williamson County Unit Road Districts | $1,758 | 1.65% | 7.1137 | $106,295 | |
| Crainville | Williamson County Unit Road Districts | $1,716 | 1.61% | 6.9436 | $106,295 | |
| Spillertown | Williamson County Unit Road Districts | $1,709 | 1.61% | 6.9128 | $106,295 | |
| Hurst | Williamson County Unit Road Districts | $1,684 | 1.58% | 6.8145 | $106,295 | |
| Freeman Spur | Williamson County Unit Road Districts | $1,661 | 1.56% | 6.7201 | $106,295 | |
| Bush | Williamson County Unit Road Districts | $1,654 | 1.56% | 6.6926 | $106,295 | |
| Colp | Williamson County Unit Road Districts | $1,566 | 1.47% | 6.3368 | $106,295 |
Williamson County compared with Illinois and the US
| Area | Effective rate | Median bill | Median home value |
|---|---|---|---|
| Williamson County | 1.71% | $2,490 | $145,600 |
| Illinois median | 2.07% | $5,189 | $250,500 |
| United States median | 0.98% | $2,969 | n/a |
Williamson County compared with neighboring counties
Williamson County borders 5 counties. Ranked from lowest to highest median effective rate, it places 5 of 6.
| County | Effective rate | Median bill | Median home value |
|---|---|---|---|
| Johnson County | 1.32% | $1,952 | $148,200 |
| Union County | 1.41% | $1,851 | $131,700 |
| Franklin County | 1.50% | $1,316 | $87,700 |
| Saline County | 1.56% | $1,445 | $92,900 |
| Williamson County | 1.71% | $2,490 | $145,600 |
| Jackson County | 1.91% | $2,385 | $125,000 |
Illinois statewide: General Homestead Exemption of up to $10,000 of equalized assessed value in Cook County, $8,000 in the counties contiguous to Cook, and $6,000 elsewhere. The Senior Citizens Homestead Exemption adds $8,000 in Cook and the contiguous counties or $5,000 elsewhere, and a senior assessment freeze is available under an income limit.
Due dates and payment
Illinois statewide: two installments, typically due June 1 and September 1 (Cook County: March 1 and August 1, often delayed). Confirm the local schedule with the Williamson County tax office.
Appealing your assessment
30 days from the township assessment notice; a second appeal to the county Board of Review follows. Bring recent sales of comparable homes, photos of condition issues, and any error in the record such as square footage or lot size. How to appeal, step by step.
How Illinois assesses value
33 1/3% of fair market value statewide; Cook County classifies property and assesses residential at 10%, then a state equalization factor is applied. Full Illinois rules, exemptions and deadlines.
Rates and medians: U.S. Census Bureau, ACS 2023 5-year estimates, tables B25103 and B25077. Effective rate is median taxes paid divided by median owner-occupied home value. Places: Census place by county reference file. Illinois cities and county rates: Illinois Department of Revenue, Property Tax Statistics, 2024 and 2023. Neighbors: Census county adjacency file. Rules: Illinois Department of Revenue, Property Tax Exemption Information (PIO-74).
Frequently asked questions
What is the property tax rate in Williamson County, IL?
The median effective property tax rate in Williamson County is 1.71% of home value, below the Illinois median of 2.07% and above the national median of 0.98%. The median homeowner pays $2,490 a year on a median home value of $145,600 (Census ACS 2023 5-year).
How much is property tax on a $400,000 house in Williamson County?
About $6,840 per year at the county's median effective rate of 1.71%, before exemptions. The exact bill depends on the city, school district and special districts that serve the parcel, so treat this as a planning estimate.
When are property taxes due in Williamson County?
Illinois statewide: two installments, typically due June 1 and September 1 (Cook County: March 1 and August 1, often delayed). Check the Williamson County tax office for the exact local dates.
How do I appeal a property tax assessment in Williamson County?
30 days from the township assessment notice; a second appeal to the county Board of Review follows. Full Illinois rules are on the Illinois page.
How does Williamson County compare with the rest of Illinois?
Williamson County ranks 63 of 102 Illinois counties by effective rate. The Illinois median is 2.07% and the median bill is $5,189.