| Rank |
County |
Population Density |
| 1 |
Cook County, Illinois
|
5,495.1
|
| 2 |
DuPage County, Illinois
|
2,799.8
|
| 3 |
Lake County, Illinois
|
1,585.6
|
| 4 |
Kane County, Illinois
|
990.8
|
| 5 |
Will County, Illinois
|
809.6
|
| 6 |
Winnebago County, Illinois
|
575.2
|
| 7 |
McHenry County, Illinois
|
511.9
|
| 8 |
St Clair County, Illinois
|
410.6
|
| 9 |
Madison County, Illinois
|
376.3
|
| 10 |
Kendall County, Illinois
|
358.2
|
| 11 |
Rock Island County, Illinois
|
345
|
| 12 |
Peoria County, Illinois
|
301.2
|
| 13 |
Sangamon County, Illinois
|
227.4
|
| 14 |
Tazewell County, Illinois
|
208.6
|
| 15 |
Champaign County, Illinois
|
201.8
|
| 16 |
Boone County, Illinois
|
193
|
| 17 |
Macon County, Illinois
|
190.8
|
| 18 |
Kankakee County, Illinois
|
167.7
|
| 19 |
DeKalb County, Illinois
|
166.6
|
| 20 |
Williamson County, Illinois
|
157.9
|
| 21 |
McLean County, Illinois
|
143.3
|
| 22 |
Grundy County, Illinois
|
119.8
|
| 23 |
Coles County, Illinois
|
106
|
| 24 |
Jackson County, Illinois
|
103.1
|
| 25 |
LaSalle County, Illinois
|
100.4
|
| 26 |
Franklin County, Illinois
|
96.8
|
| 27 |
Vermilion County, Illinois
|
90.9
|
| 28 |
Monroe County, Illinois
|
85.6
|
| 29 |
Whiteside County, Illinois
|
85.5
|
| 30 |
Stephenson County, Illinois
|
84.5
|
| 31 |
Clinton County, Illinois
|
79.7
|
| 32 |
Adams County, Illinois
|
78.5
|
| 33 |
Knox County, Illinois
|
73.9
|
| 34 |
Woodford County, Illinois
|
73.3
|
| 35 |
Effingham County, Illinois
|
71.5
|
| 36 |
Ogle County, Illinois
|
70.5
|
| 37 |
Marion County, Illinois
|
68.9
|
| 38 |
Jefferson County, Illinois
|
68
|
| 39 |
Saline County, Illinois
|
65.6
|
| 40 |
Massac County, Illinois
|
65
|
| 41 |
Morgan County, Illinois
|
62.5
|
| 42 |
Jersey County, Illinois
|
62.2
|
| 43 |
Henry County, Illinois
|
61.3
|
| 44 |
Randolph County, Illinois
|
58.2
|
| 45 |
Macoupin County, Illinois
|
55.4
|
| 46 |
McDonough County, Illinois
|
55.3
|
| 47 |
Wabash County, Illinois
|
53.5
|
| 48 |
Perry County, Illinois
|
50.6
|
| 49 |
Lee County, Illinois
|
49.7
|
| 50 |
Christian County, Illinois
|
49.1
|
| 51 |
Logan County, Illinois
|
49
|
| 52 |
Douglas County, Illinois
|
48
|
| 53 |
Bond County, Illinois
|
46.7
|
| 54 |
Lawrence County, Illinois
|
45.2
|
| 55 |
Richland County, Illinois
|
45.1
|
| 56 |
Crawford County, Illinois
|
44.7
|
| 57 |
Moultrie County, Illinois
|
44.2
|
| 58 |
Union County, Illinois
|
43.1
|
| 59 |
Montgomery County, Illinois
|
42.8
|
| 60 |
Fulton County, Illinois
|
42.8
|
| 61 |
De Witt County, Illinois
|
41.7
|
| 62 |
Menard County, Illinois
|
40.4
|
| 63 |
Bureau County, Illinois
|
40.2
|
| 64 |
Piatt County, Illinois
|
38.1
|
| 65 |
Jo Daviess County, Illinois
|
37.7
|
| 66 |
Putnam County, Illinois
|
37.5
|
| 67 |
Livingston County, Illinois
|
37.3
|
| 68 |
Johnson County, Illinois
|
36.6
|
| 69 |
Cass County, Illinois
|
36.3
|
| 70 |
Alexander County, Illinois
|
35
|
| 71 |
Carroll County, Illinois
|
34.6
|
| 72 |
Marshall County, Illinois
|
32.7
|
| 73 |
Clark County, Illinois
|
32.6
|
| 74 |
Warren County, Illinois
|
32.6
|
| 75 |
Cumberland County, Illinois
|
31.9
|
| 76 |
Pulaski County, Illinois
|
30.9
|
| 77 |
Fayette County, Illinois
|
30.9
|
| 78 |
Edwards County, Illinois
|
30.2
|
| 79 |
Edgar County, Illinois
|
29.8
|
| 80 |
White County, Illinois
|
29.6
|
| 81 |
Shelby County, Illinois
|
29.5
|
| 82 |
Clay County, Illinois
|
29.5
|
| 83 |
Mercer County, Illinois
|
29.3
|
| 84 |
Ford County, Illinois
|
29
|
| 85 |
Mason County, Illinois
|
27.2
|
| 86 |
Iroquois County, Illinois
|
26.6
|
| 87 |
Washington County, Illinois
|
26.2
|
| 88 |
Greene County, Illinois
|
25.6
|
| 89 |
Hardin County, Illinois
|
24.3
|
| 90 |
Hancock County, Illinois
|
24.1
|
| 91 |
Wayne County, Illinois
|
23.5
|
| 92 |
Brown County, Illinois
|
22.7
|
| 93 |
Scott County, Illinois
|
21.3
|
| 94 |
Stark County, Illinois
|
20.8
|
| 95 |
Calhoun County, Illinois
|
20
|
| 96 |
Pike County, Illinois
|
19.8
|
| 97 |
Jasper County, Illinois
|
19.6
|
| 98 |
Hamilton County, Illinois
|
19.5
|
| 99 |
Henderson County, Illinois
|
19.3
|
| 100 |
Gallatin County, Illinois
|
17.3
|
| 101 |
Schuyler County, Illinois
|
17.3
|
| 102 |
Pope County, Illinois
|
12.1
|