Data / Rankings / Population density / Counties in Illinois

Counties in Illinois by population density

Cook County had the highest population density of 102 counties in 2022, at 2,095.3 inhabitants per km². Pope County had the lowest, at 3.9 inhabitants per km². The median was 17.3 inhabitants per km² and the figure for Illinois was 87.7 inhabitants per km². Source: the U.S. Census Bureau.

Highest2,095.3Cook County
Lowest3.9Pope County
Median17.3102 counties
Illinois87.7History

Top 40 counties, 2022

CSVChart (SVG)

Cook CountyCook County: 2,095.3 inhabitants per km²2,095.3DuPage CountyDuPage County: 1,088.2 inhabitants per km²1,088.2Lake CountyLake County: 620 inhabitants per km²620Kane CountyKane County: 383.1 inhabitants per km²383.1Will CountyWill County: 322.9 inhabitants per km²322.9Winnebago CountyWinnebago County: 212 inhabitants per km²212McHenry CountyMcHenry County: 199.6 inhabitants per km²199.6Kendall CountyKendall County: 165.8 inhabitants per km²165.8St. Clair CountySt. Clair County: 148.4 inhabitants per km²148.4Madison CountyMadison County: 142.4 inhabitants per km²142.4Rock Island CountyRock Island County: 127.3 inhabitants per km²127.3Peoria CountyPeoria County: 111.2 inhabitants per km²111.2Sangamon CountySangamon County: 86.4 inhabitants per km²86.4Champaign CountyChampaign County: 80.6 inhabitants per km²80.6Tazewell CountyTazewell County: 77.6 inhabitants per km²77.6Boone CountyBoone County: 73 inhabitants per km²73Macon CountyMacon County: 67.3 inhabitants per km²67.3DeKalb CountyDeKalb County: 61.3 inhabitants per km²61.3Williamson CountyWilliamson County: 61.1 inhabitants per km²61.1Kankakee CountyKankakee County: 60.4 inhabitants per km²60.4McLean CountyMcLean County: 55.8 inhabitants per km²55.8Grundy CountyGrundy County: 49.1 inhabitants per km²49.1LaSalle CountyLaSalle County: 36.7 inhabitants per km²36.7Coles CountyColes County: 35.5 inhabitants per km²35.5Monroe CountyMonroe County: 35.2 inhabitants per km²35.2Franklin CountyFranklin County: 35.1 inhabitants per km²35.1Jackson CountyJackson County: 34.9 inhabitants per km²34.9Vermilion CountyVermilion County: 31 inhabitants per km²31Whiteside CountyWhiteside County: 30.8 inhabitants per km²30.8Clinton CountyClinton County: 30.2 inhabitants per km²30.2Stephenson CountyStephenson County: 29.9 inhabitants per km²29.9Adams CountyAdams County: 29.1 inhabitants per km²29.1Woodford CountyWoodford County: 28 inhabitants per km²28Effingham CountyEffingham County: 27.7 inhabitants per km²27.7Knox CountyKnox County: 26.2 inhabitants per km²26.2Ogle CountyOgle County: 26.2 inhabitants per km²26.2Marion CountyMarion County: 24.9 inhabitants per km²24.9Jefferson CountyJefferson County: 24.6 inhabitants per km²24.6Saline CountySaline County: 23.5 inhabitants per km²23.5Henry CountyHenry County: 22.8 inhabitants per km²22.8
inhabitants per km². Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09.

Full ranking

RankCounties2022
inhabitants per km²		Change on 2021
1Cook County2,095.3-1.1%
2DuPage County1,088.2-0.4%
3Lake County620-0.2%
4Kane County383.1-0.3%
5Will County322.9-0.1%
6Winnebago County212-0.6%
7McHenry County199.6+0.1%
8Kendall County165.8+1.9%
9St. Clair County148.4-0.9%
10Madison County142.4-0.5%
11Rock Island County127.3-1.1%
12Peoria County111.2-1%
13Sangamon County86.4-1%
14Champaign County80.6+0.5%
15Tazewell County77.6-0.6%
16Boone County73-0.2%
17Macon County67.3-1.4%
18DeKalb County61.3-0.9%
19Williamson County61.1-0.5%
20Kankakee County60.4-1%
21McLean County55.8-0.2%
22Grundy County49.1+0.3%
23LaSalle County36.7-0.8%
24Coles County35.5-2%
25Monroe County35.2+0.3%
26Franklin County35.1-0.7%
27Jackson County34.9-0.6%
28Vermilion County31-1.4%
29Whiteside County30.8-1.3%
30Clinton County30.2+0.4%
31Stephenson County29.9-1%
32Adams County29.1-0.9%
33Woodford County280%
34Effingham County27.7-0.6%
35Knox County26.2-1.3%
36Ogle County26.2-0.2%
37Marion County24.9-1.4%
38Jefferson County24.6-1.2%
39Saline County23.5-1%
40Henry County22.8-0.7%
41Massac County22.6-0.7%
42Morgan County22.4-0.8%
43Jersey County22.2-0.7%
44Randolph County20.1-0.9%
45Macoupin County19.8-1%
46Wabash County19.1-1.5%
47Christian County18.3-0.4%
48Douglas County18.2-0.1%
49Perry County18-0.2%
50Lee County17.8-1.8%
51McDonough County17.5-1.3%
52Logan County17-0.2%
53Bond County17-0.6%
54Richland County16.7-1.7%
55Moultrie County16.5-1.4%
56Crawford County16.1+1%
57Union County15.8-0.8%
58Montgomery County15.3-0.6%
59Johnson County15.1-0.5%
60De Witt County14.9-0.5%
61Menard County14.8-0.8%
62Fulton County14.8-0.6%
63Piatt County14.7-0.5%
64Bureau County14.6-0.4%
65Lawrence County14.1-9.8%
66Jo Daviess County14-0.7%
67Carroll County13.5-1%
68Putnam County13.4-0.5%
69Livingston County13.1-0.8%
70Cass County13-1%
71Clark County11.7-1.1%
72Marshall County11.6-0.1%
73Warren County11.6-2.1%
74Cumberland County11.5-0.6%
75Fayette County11.4+0.2%
76Clay County10.8-0.9%
77Mercer County10.7-0.5%
78White County10.6-0.9%
79Ford County10.5-1.6%
80Shelby County10.5-0.7%
81Edwards County10.5-0.3%
82Edgar County10.2-1.1%
83Pulaski County9.6-2.5%
84Washington County9.4-0%
85Iroquois County9.1-1.3%
86Mason County9.1-0.9%
87Wayne County8.6-0.7%
88Hancock County8.4-0.9%
89Greene County8.3-1.7%
90Brown County8.1-0.1%
91Alexander County8-3.4%
92Hardin County7.8-1.5%
93Scott County7.5-1.7%
94Jasper County7.2-0.3%
95Stark County7.1+0.5%
96Hamilton County7.1+0.9%
97Pike County6.8-0.4%
98Calhoun County6.6-1.3%
99Henderson County6.3-2.3%
100Schuyler County6-1.3%
101Gallatin County5.8-1.3%
102Pope County3.9-0.2%

Other periods

About this ranking

Resident population divided by land area in km². World Bank figures use mid-year population and land area excluding inland water.

United States: Census Bureau population estimates for 1 July divided by land area (water excluded) from the latest Census Gazetteer files. US tables often give people per square mile; multiply persons per km² by 2.59 to compare.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Population Estimates Program resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-09.

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Rank Counties in Illinois by population density using official data, and cite the source.
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Questions

Which county has the highest population density?

Cook County, with 2,095.3 inhabitants per km² in 2022, according to the U.S. Census Bureau.

Which county has the lowest population density?

Pope County, with 3.9 inhabitants per km² in 2022.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². Retrieved 2026-10-09.

Population density: other rankings

Counties in Illinois: more rankings