Illinois Property Tax Assessors

Williamson County, Illinois Tax Assessors' Office

Williamson County Assessors Phone Number
Williamson County Supervisor of Assessments Office
200 West Jefferson Street
Williamson County Courthouse
Marion, Illinois 62959

Where is the Williamson County Tax Assessor's Office?

The Williamson County Tax Assessor Office is located in the Williamson County Courthouse building in Marion, Illinois.

What can the Williamson County Assessor's Office do for me?

The Williamson County Tax Assessor's Office oversees the appraisal and assessment of properties as well as the billing and collection of property taxes for all taxable real estate located in Williamson County.

Contact the assessor's office if you need help with paying your property taxes, applying for a homestead exemption or other tax exemption, reporting upgrades to your home, appealing your property tax assessment, or verifying your property records.

Submitting a Williamson County property tax appeal

If you believe that your house has been unfairly overappraised (i.e. appraised at a value higher than the true market value of the property), you can attempt to get your home re-appraised at a lower value by contacting the Assessor's Office to submit a property tax appeal.

You will have to submit a form describing your property and sufficient proof that it is overassessed, including valuations of similar homes nearby as evidence. If your appeal is accepted, your home assessment (and property taxes) will be lowered as a result.

If you would like to appeal your property, call the Williamson County Assessor's Office at (618) 997 1301 and ask for a property tax appeal form. Keep in mind that property tax appeals are generally only accepted in a 1-3 month window each year.

For more information and example appeals, see how to appeal your property taxes.

Useful Williamson County Facts:

The median home value in Williamson County is between $84,887.00 and $90,313.00. Property tax rates are based on property values.

How can I contact Williamson County?

You can try contacting the Williamson County local government directly with any issues the Assessor's Office can't solve. In many counties, certain property records such as deeds are kept in the county courthouse or county archives instead of at the tax assessors' office.

The county seat for Williamson County is located in the County Courthouse in Marion, which is where the Williamson County Assessors' Office is also located. You can direct your general inquiries to Williamson County with the contact info listed below.

Williamson County Phone Number


Williamson County Fax Number


Williamson County County Courthouse Address

County Courthouse
200 W Jefferson St
Marion, IL 62959-2415

Useful Williamson County Links:

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