Illinois Population By County in 2023

Updated on August 1, 2024.

Based on the US Census Vintage data estimates, in 2023, the population of Illinois was 12,549,689. Among all Illinois counties, Cook had the highest population (5,087,072), followed by DuPage (921,213), and Lake (708,760). Hardin was the least populated county (3,569).

Hover over or click on the counties in the map below to see the populations. The data can also be found in a table below. You can use the table to sort, filter, and explore the data further.

You can see similar information for other states and by state for the United States.

See this for other years:
Illinois Population By County in 2023
Illinois Population By County in 2023
Items per page:
0 of 0
County Population % of State Population
Adams 64441 0.51
Alexander 4695 0.04
Bond 16450 0.13
Boone 53202 0.42
Brown 6294 0.05
Bureau 32729 0.26
Calhoun 4317 0.03
Carroll 15526 0.12
Cass 12596 0.10
Champaign 205644 1.64
Christian 33228 0.27
Clark 15088 0.12
Clay 12999 0.10
Clinton 36785 0.29
Coles 46060 0.37
Cook 5087072 40.53
Crawford 18300 0.15
Cumberland 10261 0.08
DeKalb 100288 0.80
De Witt 15365 0.12
Douglas 19629 0.16
DuPage 921213 7.34
Edgar 16334 0.13
Edwards 5968 0.05
Effingham 34331 0.27
Fayette 21164 0.17
Ford 13250 0.11
Franklin 37138 0.30
Fulton 32541 0.26
Gallatin 4670 0.04
Greene 11543 0.09
Grundy 53578 0.43
Hamilton 7911 0.06
Hancock 17186 0.14
Hardin 3569 0.03
Henderson 6088 0.05
Henry 48448 0.39
Iroquois 26136 0.21
Jackson 52141 0.42
Jasper 9144 0.07
Jefferson 36320 0.29
Jersey 21091 0.17
Jo Daviess 21756 0.17
Johnson 13326 0.11
Kane 514982 4.10
Kankakee 105940 0.84
Kendall 139976 1.12
Knox 48411 0.39
Lake 708760 5.65
LaSalle 108309 0.86
Lawrence 14813 0.12
Lee 33654 0.27
Livingston 35320 0.28
Logan 27590 0.22
McDonough 26839 0.21
McHenry 312800 2.49
McLean 170441 1.36
Macon 100591 0.80
Macoupin 44018 0.35
Madison 262752 2.09
Marion 36673 0.29
Marshall 11683 0.09
Mason 12523 0.10
Massac 13661 0.11
Menard 11954 0.10
Mercer 15487 0.12
Monroe 34957 0.28
Montgomery 27663 0.22
Morgan 32140 0.26
Moultrie 14342 0.11
Ogle 51265 0.41
Peoria 177513 1.41
Perry 20503 0.16
Piatt 16714 0.13
Pike 14342 0.11
Pope 3707 0.03
Pulaski 4911 0.04
Putnam 5561 0.04
Randolph 29815 0.24
Richland 15488 0.12
Rock Island 141236 1.13
St. Clair 251018 2.00
Saline 22873 0.18
Sangamon 193491 1.54
Schuyler 6733 0.05
Scott 4710 0.04
Shelby 20568 0.16
Stark 5218 0.04
Stephenson 43105 0.34
Tazewell 129541 1.03
Union 16667 0.13
Vermilion 71652 0.57
Wabash 10942 0.09
Warren 16185 0.13
Washington 13536 0.11
Wayne 15761 0.13
White 13401 0.11
Whiteside 54498 0.43
Will 700728 5.58
Williamson 66706 0.53
Winnebago 280922 2.24
Woodford 38285 0.31