simplemaplab

Illinois County Map With Cities

By Marko Visic · Updated Oct 5, 2026

Illinois has 102 counties, covering 55,514 square miles of land. The Census Bureau estimates its population at 12,719,141 as of July 1, 2025. The largest county by land area is McLean County; the most populous is Cook County; the least populous is Hardin County.

Counties
102
Population
12,719,141
Land area
55,514 sq mi
Capital
Springfield
Time Zone
Central (CT)

Tap or click any county for details. Need a printable version? Blank Illinois map (PDF/PNG/SVG).

All 102 Illinois counties

County FIPS code Population (July 1, 2025) ▼Change since April 2020 Land area (sq mi) People per sq mi Median household income (2020–2024)
Cook County170315,194,625-1.6%9455,497$83,498
DuPage County17043934,298+0.1%3282,849$112,096
Lake County17097719,339+0.7%4441,621$110,416
Will County17197712,253+2.1%836852$109,984
Kane County17089525,757+1.8%5191,012$103,163
McHenry County17111317,751+2.4%603527$104,802
Winnebago County17201283,674-0.6%513553$65,837
Madison County17119263,110-1.1%716368$75,793
St. Clair County17163250,708-2.7%658381$73,854
Champaign County17019209,972+1.7%996211$63,683
Sangamon County17167194,170-1.1%868224$75,357
Peoria County17143178,553-1.9%619289$65,108
McLean County17113171,419+0.1%1,183145$79,905
Kendall County17093145,470+10.3%320454$111,601
Rock Island County17161141,869-1.9%427332$67,159
Tazewell County17179130,049-1.1%646201$77,982
LaSalle County17099107,773-1.7%1,13595$73,045
Kankakee County17091105,525-2.0%676156$71,281
DeKalb County17037101,835+1.3%631161$70,724
Macon County1711599,300-4.5%581171$62,666
Vermilion County1718371,259-4.0%89879$56,877
Williamson County1719967,225+0.1%420160$65,604
Adams County1700164,267-2.2%85575$66,220
Whiteside County1719554,121-2.8%68479$67,500
Grundy County1706354,052+2.8%418129$92,235
Boone County1700753,568+0.2%281191$84,571
Jackson County1707752,501-1.6%58490$48,763
Ogle County1714151,399-0.9%75968$82,132
Henry County1707348,095-2.4%82358$71,911
Knox County1709547,767-4.4%71667$57,030
Coles County1702946,607-1.2%50892$56,478
Macoupin County1711743,748-2.9%86351$70,805
Stephenson County1717743,220-3.3%56477$64,043
Woodford County1720338,111-0.9%52872$91,483
Clinton County1702737,128+0.6%47478$86,588
Franklin County1705536,916-2.3%40990$56,740
Marion County1712136,382-3.6%57364$61,240
Jefferson County1708136,147-2.6%57163$63,118
Livingston County1710535,057-2.2%1,04434$73,790
Monroe County1713334,840-0.3%38590$102,880
Effingham County1704934,519-0.4%47972$80,404
Christian County1702133,443-1.8%70947$62,611
Lee County1710332,914-3.6%72545$70,292
Fulton County1705732,901-2.3%86638$60,599
Morgan County1713732,515-3.1%56957$66,306
Bureau County1701132,510-2.3%86937$69,257
Randolph County1715729,921-0.8%57552$68,131
Montgomery County1713528,076-0.9%70440$63,620
Logan County1710727,182-2.9%61844$66,358
Iroquois County1707526,150-3.4%1,11723$66,255
McDonough County1710925,916-4.9%58944$52,795
Saline County1716522,772-4.4%38060$53,117
Jo Daviess County1708521,594-2.2%60136$73,993
Jersey County1708321,160-1.7%37057$80,361
Fayette County1705120,790-3.3%71629$60,944
Shelby County1717320,576-2.0%75927$72,095
Perry County1714520,160-3.7%44246$62,118
Douglas County1704119,880+0.7%41748$77,320
Crawford County1703318,6480.0%44442$71,674
Bond County1700516,959+0.4%38045$65,959
Hancock County1706716,803-4.8%79421$65,865
Piatt County1714716,791+0.6%43938$94,811
Union County1718116,656-4.0%41340$55,728
Edgar County1704516,323-3.3%62326$59,941
Warren County1718716,222-3.7%54230$67,385
Wayne County1719115,882-1.9%71422$55,521
Carroll County1701515,419-1.9%44535$60,758
Mercer County1713115,229-3.0%56127$74,182
Richland County1715915,219-3.8%36042$62,455
De Witt County1703915,118-2.5%39838$71,678
Clark County1702315,114-2.4%50130$72,927
Moultrie County1713914,371-1.1%33643$71,784
Pike County1714914,231-3.4%83117$59,777
Lawrence County1710113,790-9.9%37237$55,324
Washington County1718913,564-1.5%56324$78,224
Massac County1712713,502-4.8%23757$65,116
Johnson County1708713,363+0.4%34439$62,528
White County1719313,250-4.5%49527$54,813
Ford County1705313,216-2.3%48627$62,439
Clay County1702512,793-3.7%46827$60,417
Cass County1701712,463-4.4%37633$68,125
Mason County1712512,411-5.1%53923$62,845
Menard County1712911,863-3.5%31438$82,176
Marshall County1712311,473-2.4%38730$71,585
Greene County1706111,313-5.5%54321$62,192
Wabash County1718510,907-4.0%22349$57,086
Cumberland County1703510,208-2.3%34630$73,327
Jasper County170799,032-2.9%49518$74,755
Hamilton County170657,859-1.7%43518$65,746
Schuyler County171696,657-3.5%43715$65,948
Brown County170096,401+2.5%30621$67,917
Henderson County170715,984-6.4%37916$62,227
Edwards County170475,898-5.5%22227$60,519
Putnam County171555,619-0.2%16035$75,590
Stark County171755,319-1.4%28818$62,878
Scott County171714,866-4.1%25119$66,705
Pulaski County171534,820-7.4%19924$42,463
Gallatin County170594,616-6.6%32314$59,219
Alexander County170034,570-12.8%23519$47,043
Calhoun County170134,300-2.9%25417$93,203
Pope County171513,672-2.5%36910$60,050
Hardin County170693,588-1.9%17720$54,271

FIPS code: the Census Bureau’s five-digit county ID, a two-digit state code plus a three-digit county code. It is not a ZIP code.

How many counties does Illinois have?

Illinois has 102 counties covering 55,514 square miles. The state was admitted to the Union in 1818 as the 21st state.

The largest county by land area is McLean County at 1,183 square miles, home to 171,419 residents. The most populous is Cook County with 5,194,625 residents — a density of 5,497 people per square mile. At the other end of the scale, Hardin County has 3,588 residents.

Illinois’s capital is Springfield, while the largest city is Chicago.

Related resources

Download a printable outline of Illinois’s county boundaries from our blank map of Illinois page — available in SVG, PNG, and PDF.

Use the What County Am I In? tool to detect which Illinois county a GPS location or address falls in, or the Address to County Lookup for batch input.

For demographic radius analysis, the Find ZIP Codes in Radius and Population Within Radius tools let you draw a circle around any Illinois address and see every ZIP code and the total population inside.

Two SimpleMapLab studies cover Illinois specifically: the 100-mile radius around Springfield measures how much of the state lives within 100 miles of its capitol, and the loneliest town in Illinois ranks the state’s most isolated inhabited place. The county-counts blog post puts Illinois’s 102 counties in national context.

Frequently asked questions

Illinois has 102 counties. The state was admitted to the Union in 1818 as the 21st state. County boundaries have shifted over time as the population spread and new administrative units were carved from existing ones.
McLean County is the largest by land area at 1,183 square miles, with 171,419 residents.
Cook County is the most populous, with 5,194,625 residents over 945 square miles.
Hardin County has the smallest population at 3,588 residents.
Springfield is the state capital of Illinois. The largest city is Chicago.
County population is the US Census Bureau's Vintage 2025 estimate for July 1, 2025; land and water area are from the 2026 Census Gazetteer; median household income is from the American Community Survey 2020–2024 5-year estimates. The county boundaries drawn on the map are the US Atlas TopoJSON build of the Census Bureau's TIGER/Line shapefiles. All figures are US Census Bureau data in the public domain.
Data sources

Neighboring states

Iowa
99 counties
Indiana
92 counties
Kentucky
120 counties
Missouri
114 counties + 1 city
Wisconsin
72 counties