Illinois
102 counties · Pop: 12,812,508
State Offices
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Counties in Illinois
Adams
County Seat: Quincy
Pop: 65,435
Alexander
County Seat: Cairo
Pop: 5,765
Bond
County Seat: Greenville
Pop: 16,426
Boone
County Seat: Belvidere
Pop: 53,448
Brown
County Seat: Mount Sterling
Pop: 6,578
Bureau
County Seat: Princeton
Pop: 32,628
Calhoun
County Seat: Hardin
Pop: 4,616
Carroll
County Seat: Mount Carroll
Pop: 14,305
Cass
County Seat: Virginia
Pop: 11,922
Champaign
County Seat: Urbana
Pop: 205,865
Christian
County Seat: Taylorville
Pop: 32,304
Clark
County Seat: Marshall
Pop: 15,441
Clay
County Seat: Louisville
Pop: 13,184
Clinton
County Seat: Carlyle
Pop: 37,562
Coles
County Seat: Charleston
Pop: 50,621
Cook
County Seat: Chicago
Pop: 5,275,541
Crawford
County Seat: Robinson
Pop: 18,469
Cumberland
County Seat: Toledo
Pop: 10,766
De Witt
County Seat: Clinton
Pop: 15,638
DeKalb
County Seat: Sycamore
Pop: 104,897
Douglas
County Seat: Tuscola
Pop: 19,465
DuPage
County Seat: Wheaton
Pop: 932,877
Edgar
County Seat: Paris
Pop: 17,161
Edwards
County Seat: Albion
Pop: 6,395
Effingham
County Seat: Effingham
Pop: 34,151
Fayette
County Seat: Vandalia
Pop: 21,336
Ford
County Seat: Paxton
Pop: 12,961
Franklin
County Seat: Benton
Pop: 38,469
Fulton
County Seat: Lewistown
Pop: 34,343
Gallatin
County Seat: Shawneetown
Pop: 4,793
Greene
County Seat: Carrollton
Pop: 12,969
Grundy
County Seat: Morris
Pop: 51,464
Hamilton
County Seat: McLeansboro
Pop: 8,116
Hancock
County Seat: Carthage
Pop: 17,612
Hardin
County Seat: Elizabethtown
Pop: 3,821
Henderson
County Seat: Oquawka
Pop: 6,646
Henry
County Seat: Cambridge
Pop: 48,913
Iroquois
County Seat: Watseka
Pop: 27,114
Jackson
County Seat: Murphysboro
Pop: 57,517
Jasper
County Seat: Newton
Pop: 9,610
Jefferson
County Seat: Mount Vernon
Pop: 37,684
Jersey
County Seat: Jerseyville
Pop: 22,773
Jo Daviess
County Seat: Galena
Pop: 21,235
Johnson
County Seat: Vienna
Pop: 12,417
Kane
County Seat: Geneva
Pop: 516,522
Kankakee
County Seat: Kankakee
Pop: 109,862
Kendall
County Seat: Yorkville
Pop: 131,869
Knox
County Seat: Galesburg
Pop: 49,699
Lake
County Seat: Waukegan
Pop: 714,342
LaSalle
County Seat: Ottawa
Pop: 108,669
Lawrence
County Seat: Lawrenceville
Pop: 15,678
Lee
County Seat: Dixon
Pop: 34,096
Livingston
County Seat: Pontiac
Pop: 35,648
Logan
County Seat: Lincoln
Pop: 28,618
Macon
County Seat: Decatur
Pop: 104,009
Macoupin
County Seat: Carlinville
Pop: 44,926
Madison
County Seat: Edwardsville
Pop: 264,776
Marion
County Seat: Salem
Pop: 37,205
Marshall
County Seat: Lacon
Pop: 11,438
Mason
County Seat: Havana
Pop: 13,359
Massac
County Seat: Metropolis
Pop: 13,772
McDonough
County Seat: Macomb
Pop: 29,682
McHenry
County Seat: Woodstock
Pop: 310,229
McLean
County Seat: Bloomington
Pop: 172,164
Menard
County Seat: Petersburg
Pop: 12,196
Mercer
County Seat: Aledo
Pop: 15,437
Monroe
County Seat: Waterloo
Pop: 35,251
Montgomery
County Seat: Hillsboro
Pop: 28,414
Morgan
County Seat: Jacksonville
Pop: 33,658
Moultrie
County Seat: Sullivan
Pop: 14,505
Ogle
County Seat: Oregon
Pop: 51,032
Peoria
County Seat: Peoria
Pop: 180,786
Perry
County Seat: Pinckneyville
Pop: 20,916
Piatt
County Seat: Monticello
Pop: 16,344
Pike
County Seat: Pittsfield
Pop: 15,561
Pope
County Seat: Golconda
Pop: 4,177
Pulaski
County Seat: Mound City
Pop: 5,193
Putnam
County Seat: Hennepin
Pop: 5,746
Randolph
County Seat: Chester
Pop: 31,782
Richland
County Seat: Olney
Pop: 15,513
Rock Island
County Seat: Rock Island
Pop: 142,815
Saline
County Seat: Harrisburg
Pop: 23,491
Sangamon
County Seat: Springfield
Pop: 194,672
Schuyler
County Seat: Rushville
Pop: 6,768
Scott
County Seat: Winchester
Pop: 4,951
Shelby
County Seat: Shelbyville
Pop: 21,634
St. Clair
County Seat: Belleville
Pop: 257,400
Stark
County Seat: Toulon
Pop: 5,378
Stephenson
County Seat: Freeport
Pop: 44,498
Tazewell
County Seat: Pekin
Pop: 131,803
Union
County Seat: Jonesboro
Pop: 16,653
Vermilion
County Seat: Danville
Pop: 75,758
Wabash
County Seat: Mount Carmel
Pop: 11,520
Warren
County Seat: Monmouth
Pop: 16,844
Washington
County Seat: Nashville
Pop: 13,887
Wayne
County Seat: Fairfield
Pop: 16,215
White
County Seat: Carmi
Pop: 13,537
Whiteside
County Seat: Morrison
Pop: 55,005
Will
County Seat: Joliet
Pop: 690,743
Williamson
County Seat: Marion
Pop: 66,929
Winnebago
County Seat: Rockford
Pop: 282,572
Woodford
County Seat: Eureka
Pop: 38,664