List of counties in Illinois

The links in the column are to the Census Bureau Info page for that county. Listed are the 102 in the  of.

Defunct counties

 * was renamed in 1840 to the current.
 * The original Knox County, Illinois, became extinct with the formation of the in 1809 - or, more precisely, it became . The modern  was formed much later, and was not a part of the original Knox County.

External links and sources

 * Census 2000 Gazetteer
 * Illinois Association of County Board Members and Commissioners
 * Illinois City/County Management Association
 * National Association of Counties