LaSalle County, IL Property Tax: $3,336/yr (2026)
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The effective property tax rate in LaSalle County is 2.15% of assessed home value. On a home at the county median value of $154,900, that works out to about $3,330 per year, or $278 per month. LaSalle County is located in northern Illinois, with part of the Ottawa as its county seat, and is home to approximately 109,049 residents.
About LaSalle County
LaSalle County covers approximately 1,135.1 square miles in Illinois. The county is home to about 109,049 residents living in roughly 49,838 housing units, of which 66.9% are owner-occupied. The median household income is $72,281, and the median home was built in 1963.
The county seat is part of the Ottawa. LaSalle County borders Bureau County, DeKalb County, Grundy County, Kendall County, Lee County — useful comparisons if you're considering nearby areas with potentially different tax rates.
How Property Taxes Work in Illinois
Property taxes in Illinois are administered at the county level. Each county sets a millage rate applied to the assessed value of real property — the effective rate above accounts for any partial assessments and exemptions already built into the local tax base. Assessed value can differ meaningfully from current market value depending on how often the county reassesses and what fraction of market value it uses.
Most counties in Illinois offer exemptions that reduce the taxable assessed value: homestead exemptions for primary residences, senior exemptions, disability exemptions, and veteran exemptions are common. These reduce your effective rate below the county-wide average shown here. Contact the LaSalle County Assessor's office to learn which exemptions apply to your property and when to file.
LaSalle County vs. Neighboring Counties
| Location | Eff. Rate | Median Home | Annual Tax |
|---|---|---|---|
| LaSalle County, IL | 2.15% | $154,900 | $3,330 |
| Illinois state average | 1.83% | — | $2,835* |
| Bureau County | 2.07% | $121,900 | $2,522 |
| DeKalb County | 2.54% | $231,900 | $5,889 |
| Grundy County | 2.03% | $259,200 | $5,260 |
| Kendall County | 2.53% | $298,900 | $7,556 |
| Lee County | 1.92% | $155,100 | $2,980 |
| US national average | 1.10% | $281,900 | $3,101 |
*State average annual tax computed at LaSalle County's median home value of $154,900. Source: US Census ACS 2023 5-year estimates.
Frequently Asked Questions
How does LaSalle County's property tax rate compare to the rest of Illinois?
At 2.15%, LaSalle County is higher than the Illinois state average of 1.83%. On a home at the county median of $154,900, that means about $3,330 per year — versus $2,835 at the state average rate, a difference of $495 per year. Compared to the national average of 1.10%, LaSalle County is above average.
What's a typical annual property tax bill in LaSalle County?
For a home at the county median value of $154,900, the annual property tax in LaSalle County is approximately $3,330 — or about $278 per month. For a home worth $232,350, expect around $4,996 per year. For a $309,800 home, approximately $6,661 per year. Use the calculator above to estimate taxes for any assessed value.
Where do I appeal a LaSalle County property tax assessment?
Property assessment appeals in LaSalle County are handled by the LaSalle County Assessor's office in part of the Ottawa. Most jurisdictions require filing within 30–90 days of receiving your assessment notice — confirm the specific deadline with the assessor's office before submitting, as deadlines and procedures vary by county. A successful appeal can reduce your assessed value and lower your tax bill for the current and future tax years.
What exemptions are available in LaSalle County?
Illinois counties commonly offer homestead exemptions for owner-occupied primary residences, senior citizen exemptions for qualifying homeowners aged 65 and older, exemptions for disabled residents, and veterans' exemptions. Each exemption reduces your assessed taxable value, which in turn reduces your effective tax rate below the county-wide 2.15% shown here. Contact the LaSalle County Assessor's office to confirm which exemptions are available and the application deadlines.
Data sources: US Census Bureau ACS 2023 5-Year Estimates, US Census Gazetteer (2024), County Adjacency File