Ranking of Illinois Counties By Population in 2019

Updated on January 28, 2024.

Based on the US Census Vintage data estimates, in 2019, the Population for Illinois was 12.67M. Among all Illinois counties, Cook County had the highest population (5.15M), followed by DuPage County (922.76K), and Lake County (697.13K).

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 2019
Cook
5.15M
DuPage
922.76K
Lake
697.13K
Will
690.18K
Kane
532.29K
McHenry
307.44K
Winnebago
282.46K
Madison
263.61K
St. Clair
259.89K
Champaign
209.61K
Ranking of Illinois Counties By Population in 2019
Rank
County
Population
1 Cook County 5,145,326
2 DuPage County 922,761
3 Lake County 697,134
4 Will County 690,176
5 Kane County 532,293
6 McHenry County 307,439
7 Winnebago County 282,465
8 Madison County 263,609
9 St. Clair County 259,889
10 Champaign County 209,612
11 Sangamon County 194,882
12 Peoria County 179,359
13 McLean County 171,272
14 Rock Island County 141,775
15 Tazewell County 131,848
16 Kendall County 128,900
17 Kankakee County 109,569
18 LaSalle County 108,517
19 DeKalb County 105,131
20 Macon County 104,012
21 Vermilion County 75,736
22 Williamson County 66,633
23 Adams County 65,402
24 Jackson County 56,844
25 Whiteside County 55,215
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