Property tax in Knox County, Illinois
In Knox County, the property tax bill comes from the Knox County Treasurer (the county collector). You can look up and pay the bill on the county's own payment page. Taken from Knox County's own pages, checked September 23, 2026.
The median property tax bill in Knox County, Illinois is $2,190 a year, which is about 1.96% of the county's median home value of $111,900. That effective rate is higher than the typical Illinois county (1.81%) and higher than the national median (0.81%). These are American Community Survey 5-year estimates (2024); your own bill depends on your home's assessed value and any exemptions.
Who sends the property tax bill in Knox County, and how do you pay it?
The bill comes from the Knox County Treasurer (the county collector). The value it is based on is set by a separate office, the Knox County Supervisor of Assessments, with the township assessors, which is who to ask if the value looks wrong. For how to look up and pay the bill, go to the county's own payment information.
Township assessors value homes, and the county Supervisor of Assessments reviews their work and handles exemptions. One county bill carries the taxes of every local district the property sits in, such as school districts, cities, fire and sanitary districts and the community college. Tax bills and payment status can be looked up on the county's online property tax inquiry. A Board of Review decision can be appealed to the Illinois Property Tax Appeal Board within 30 days of the postmark date on the Board's written decision.
When are property taxes due in Knox County?
Two installments by default, the first due June 1 and the second September 1, or the date on the bill if later. Cook County and counties using accelerated billing follow different schedules, and the county collector sets the actual dates.
Knox County does not publish the due dates for its bill on its own pages (checked September 23, 2026), so we do not print any here. The dates on your statement are the ones that bind you; who sends which bill is covered above.
Estimate the property tax on a home in Knox County
Enter a home's market value for a ballpark at Knox County's average effective rate of 1.96% (Census). The real bill depends on the home's assessed value, the millage where it sits and any exemptions.
Estimated property tax: $2,193 / year
Property tax in Knox County at a glance
| Measure | Value |
|---|---|
| Median annual property tax | $2,190 |
| Median home value | $111,900 |
| Effective tax rate | 1.96% |
| Typical Illinois county rate | 1.81% |
| National median county rate | 0.81% |
Effective rate = median real estate taxes paid divided by median home value. Source: U.S. Census Bureau, American Community Survey 5-year estimates.
How does Knox County compare in Illinois?
Among Illinois's 102 counties, Knox County has the 35th highest effective property-tax rate: 34 rank higher and 67 rank lower. That is on the higher side for Illinois. Nationally, it ranks 97th of 3135 US counties by effective rate. See every Illinois county ranked.
How much do homeowners in Knox County actually pay?
The median is only the middle bill. Across Knox County's 14,852 owner-occupied homes, 32.1% pay $3,000 or more a year in property tax, 52.1% pay at least $2,000, and 13.9% pay under $800. Another 3.3% report paying no property tax at all, which usually means an exemption covers the whole bill.
| Annual bill | Homes | Share |
|---|---|---|
| Under $800 | 2,063 | 13.9% |
| $800 to $1,499 | 2,646 | 17.8% |
| $1,500 to $1,999 | 1,902 | 12.8% |
| $2,000 to $2,999 | 2,976 | 20% |
| $3,000 or more | 4,768 | 32.1% |
| No property tax paid | 497 | 3.3% |
Owners with a mortgage pay a median of $2,451 and owners without one pay $1,872. Owners who have paid off a home have usually held it longer, and in states that cap how fast an existing owner's assessment can rise, long-held homes carry lower assessed values. Census table B25103.
How does the Knox County property tax bill compare with local incomes?
The median property tax bill of $2,190 is about 3.1% of the median income of Knox County homeowner households, $71,626 a year. That compares two middles, so a retiree in a long-held home can pay a far larger share. 70.8% of Knox County's occupied homes are lived in by their owners; renters pay property tax too, just folded into rent.
Have property taxes gone up in Knox County?
Yes. The median bill went from $1,686 in 2015-2019 to $2,190 in 2020-2024, a 29.9% rise. Over the same span the median home value moved 34.8%, from $83,000 to $111,900.
Two Census ACS 5-year periods with no survey years in common, in each period's own dollars. A change counts only if it exceeds the combined 90% margin of error.
Property tax in counties next to Knox County
Knox County borders 6 counties.
| County | Effective rate | Median bill | Median home value |
|---|---|---|---|
| Peoria County, IL | 2.24% | $3,552 | $158,500 |
| Fulton County, IL | 2.14% | $2,289 | $107,200 |
| Henry County, IL | 1.99% | $3,016 | $151,600 |
| Mercer County, IL | 1.96% | $2,878 | $146,700 |
| Knox County, IL (this county) | 1.96% | $2,190 | $111,900 |
| Warren County, IL | 1.81% | $1,903 | $105,000 |
| Stark County, IL | 1.69% | $1,768 | $104,500 |
How is a home assessed in Knox County?
Illinois assesses homes at 33.33% of market value in every county, Knox County included. How Illinois assesses and reappraises homes.
Is there a homestead exemption in Knox County?
Yes. Illinois's General Homestead Exemption is $6,000 of equalized assessed value in most counties, $8,000 in counties next to Cook, and $10,000 in Cook County. That is the Illinois rule, and it applies in Knox County. Illinois's exemptions and relief programs in full.
How to appeal your Knox County property assessment
In Knox County you appeal to the Knox County Board of Review. The deadline: A written appeal, with its supporting documents, must be filed with the Board of Review within 30 days after the county publishes the year's assessment list. The Board sets the exact date each year; the 2026 date had not been confirmed as of September 23, 2026. How to file. Checked September 23, 2026 against state law, because Knox County does not restate them on its own pages.
How Illinois's appeal process works, including the next level if the first one turns you down.
Illinois rules from primary state sources, reviewed September 7, 2026; sources on the Illinois page.
Work out your own numbers
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How much house can I afford?
Your income, debts and down payment against the 28/36 rule lenders actually use, with Knox County's tax rate to hand.
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Mortgage calculator
Monthly payment with principal, interest, tax and insurance, plus what an extra payment saves you.
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Illinois income tax
Brackets, standard deduction and what Illinois actually taxes.
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Sales tax in Knox County
The other local tax: combined state and local rate for this county.
Sources
- Median real estate taxes paid and median home value for Knox County, Illinois: U.S. Census Bureau, American Community Survey 5-year estimates (2020-2024), tables B25103, B25077, B25102, B25119 and B25003; the five-year comparison uses the 2015-2019 estimates. Neighboring counties: Census county adjacency file.