Ranking of Illinois Counties By Population in 2023

Updated on June 21, 2025.

Based on the US Census Vintage data estimates, in 2023, the Population for Illinois was 12.64M. Among all Illinois counties, Cook County had the highest population (5.14M), followed by DuPage County (929.18K), and Lake County (714.21K).

The chart below shows the top 10 counties, and the table below shows the ranking of all Illinois counties.

You can see similar ranking information for related topics, and for other states. You can also see the ranking of all counties in the United States.

See this for other years:
Ranking of Illinois Counties By Population in 2023
Cook
DuPage
Lake
Will
Kane
McHenry
Winnebago
Madison
St. Clair
Champaign
Ranking of Illinois Counties By Population in 2023
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Rank County Population
1 Cook County 5142522
2 DuPage County 929180
3 Lake County 714207
4 Will County 703383
5 Kane County 517241
6 McHenry County 313435
7 Winnebago County 282214
8 Madison County 263442
9 St. Clair County 252094
10 Champaign County 209813
11 Sangamon County 194216
12 Peoria County 178735
13 McLean County 171493
14 Rock Island County 141939
15 Kendall County 140229
16 Tazewell County 129835
17 LaSalle County 108397
18 Kankakee County 106386
19 Macon County 100754
20 DeKalb County 100661
21 Vermilion County 71551
22 Williamson County 66737
23 Adams County 64435
24 Whiteside County 54582
25 Grundy County 53587
26 Boone County 53239
27 Jackson County 52867
28 Ogle County 51391
29 Knox County 48663
30 Henry County 48362
31 Coles County 46532
32 Macoupin County 44127
33 Stephenson County 43347
34 Woodford County 38387
35 Franklin County 37156
36 Clinton County 36886
37 Marion County 36640
38 Jefferson County 36331
39 Livingston County 35321
40 Monroe County 35144
41 Effingham County 34453
42 Lee County 33606
43 Christian County 33319
44 Morgan County 32773
45 Bureau County 32758
46 Fulton County 32664
47 Randolph County 29993
48 Montgomery County 27756
49 Logan County 27508
50 McDonough County 26952
51 Iroquois County 26033
52 Saline County 22988
53 Jo Daviess County 21749
54 Fayette County 21209
55 Jersey County 21158
56 Shelby County 20593
57 Perry County 20499
58 Douglas County 19733
59 Crawford County 18342
60 Hancock County 17195
61 Union County 16866
62 Piatt County 16720
63 Bond County 16637
64 Edgar County 16442
65 Warren County 16224
66 Wayne County 15875
67 Richland County 15502
68 Carroll County 15492
69 Mercer County 15456
70 De Witt County 15331
71 Clark County 15218
72 Lawrence County 14886
73 Pike County 14339
74 Moultrie County 14327
75 Massac County 13751
76 Washington County 13570
77 White County 13482
78 Johnson County 13355
79 Ford County 13316
80 Clay County 12945
81 Cass County 12779
82 Mason County 12588
83 Menard County 11996
84 Marshall County 11650
85 Greene County 11572
86 Wabash County 11032
87 Cumberland County 10272
88 Jasper County 9156
89 Hamilton County 7886
90 Schuyler County 6725
91 Brown County 6301
92 Henderson County 6105
93 Edwards County 6021
94 Putnam County 5588
95 Stark County 5267
96 Pulaski County 4957
97 Scott County 4850
98 Alexander County 4723
99 Gallatin County 4708
100 Calhoun County 4293
101 Pope County 3715
102 Hardin County 3599