Population
|
County
|
5,150,233
|
Cook
|
922,921
|
Dupage
|
696,535
|
Lake
|
690,743
|
Will
|
532,403
|
Kane
|
307,774
|
McHenry
|
282,572
|
Winnebago
|
262,966
|
Madison
|
259,686
|
St. Clair
|
209,689
|
Champaign
|
194,672
|
Sangamon
|
179,179
|
Peoria
|
171,517
|
McLean
|
141,879
|
Rock Island
|
131,803
|
Tazewell
|
128,990
|
Kendall
|
109,862
|
Kankakee
|
108,669
|
LaSalle
|
104,897
|
DeKalb
|
104,009
|
Macon
|
75,758
|
Vermilion
|
66,597
|
Williamson
|
65,435
|
Adams
|
56,750
|
Jackson
|
55,175
|
Whiteside
|
53,544
|
Boone
|
51,054
|
Grundy
|
50,643
|
Ogle
|
50,621
|
Coles
|
49,699
|
Knox
|
48,913
|
Henry
|
44,926
|
Macoupin
|
44,498
|
Stephenson
|
38,923
|
Franklin
|
|
Population
|
County
|
38,459
|
Woodford
|
37,684
|
Jefferson
|
37,562
|
Clinton
|
37,205
|
Marion
|
35,648
|
Livingston
|
34,637
|
Monroe
|
34,340
|
Fulton
|
34,096
|
Lee
|
34,008
|
Effingham
|
33,658
|
Morgan
|
32,628
|
Bureau
|
32,304
|
Christian
|
32,295
|
Randolph
|
29,682
|
McDonough
|
28,828
|
Montgomery
|
28,618
|
Logan
|
27,812
|
Iroquois
|
23,994
|
Saline
|
21,773
|
Jersey
|
21,737
|
Shelby
|
21,588
|
Jo Daviess
|
21,565
|
Fayette
|
21,251
|
Perry
|
19,623
|
Douglas
|
18,972
|
Crawford
|
17,708
|
Hancock
|
17,407
|
Edgar
|
17,146
|
Warren
|
16,968
|
Union
|
16,426
|
Bond
|
16,402
|
Wayne
|
16,344
|
Piatt
|
16,033
|
Lawrence
|
15,932
|
DeWitt
|
|
Population
|
County
|
15,766
|
Richland
|
15,716
|
Clark
|
15,672
|
Pike
|
15,437
|
Mercer
|
14,641
|
Moultrie
|
14,466
|
Carroll
|
14,058
|
Washington
|
13,868
|
White
|
13,772
|
Massac
|
13,621
|
Mason
|
13,287
|
Clay
|
13,270
|
Ford
|
13,132
|
Greene
|
12,493
|
Cass
|
12,417
|
Johnson
|
12,196
|
Menard
|
11,546
|
Wabash
|
11,438
|
Marshall
|
10,766
|
Cumberland
|
9,594
|
Jasper
|
8,176
|
Hamilton
|
6,953
|
Schuyler
|
6,646
|
Henderson
|
6,628
|
Brown
|
6,455
|
Edwards
|
5,761
|
Alexander
|
5,739
|
Putnam
|
5,510
|
Pulaski
|
5,342
|
Stark
|
5,064
|
Gallatin
|
4,951
|
Scott
|
4,739
|
Calhoun
|
4,203
|
Pope
|
3,939
|
Hardin
|
|