List of counties in Illinois

Counties of Illinois
JD SN WI ↑ BN MH LK CK WL DP KA KE DK LE OG CR WS ←RI MR HE BU PM ML LS GY KK IQ FD LV WF PE ST KX WR HD HK MU SR FN MS TZ ME LO DW MC PT CH VE ED DG CO MT SH CN SA MD CS BR AD PK MG SC GR CA→ JY MP MY MI BD FA EF CD CL JA CF LA RH CY MN CT CI MO RA WA JE WN ES ←WB WH HM FK PY JK WM SL GA ←HA PO JN UN AL→ PU MA
Location	State of Illinois
Number	102
Populations	4,836 (Hardin) – 5,194,675 (Cook)
Areas	160 square miles (410 km2) (Putnam) – 1,184 square miles (3,070 km2) (McLean)
Government	County government
Subdivisions	261 Precincts 1,433 Townships

There are 102 counties in the state of Illinois.

Most counties in Illinois were named after early American leaders, especially of the American Revolutionary War, as well as soldiers from the Battle of Tippecanoe and the War of 1812. Some are named after natural features or counties in other states. Some are named for early Illinois leaders. Two counties are named for Native American tribes, and one bears the name of a plant used as a food source by Native Americans.

While it does have a city, Illinois does not have a Lincoln County named after its favorite son, Abraham Lincoln; it does, however, have a Douglas County (founded 1859) named after his political rival Stephen A. Douglas. It also has Calhoun County (founded 1825), named after John C. Calhoun, outspoken for his pro-slavery and pro-southern views in the years preceding the American Civil War. Several of the counties are named after Southerners, reflecting the fact that Illinois was for a short time part of Virginia, and settled in its early years by many Southerners. No counties are named after Northern heroes of the Civil War, mainly because the counties were all named before that war. The state does have a Lee County named after the family of Robert E. Lee, who at one time served in Illinois. Illinois also has two counties named after the same person, New York governor DeWitt Clinton (this may be unusual, but it is not unprecedented since Virginia has had two counties named after Patrick Henry since 1790).