RANKING · 1990 CENSUS · 102 SHOWN OF 102

Most densely populated, Illinois counties · 1990

Illinois counties ranked by residents per square mile (2023). This list covers the 102 counties in Illinois that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros

RELATEDLargest by population Fastest growing Fastest shrinking Most sparsely populated Best broadband access Worst broadband access

YEAR1990 2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION DENSITYVS 2000

01Cook County, ILIL5,194,6255,403−5%

02DuPage County, ILIL934,2982,384−14%

03Lake County, ILIL719,3391,164−20%

04Kane County, ILIL525,757611−21%

05Winnebago County, ILIL283,674493−9%

06Will County, ILIL712,253427−29%

07St. Clair County, ILIL250,708400+3%

08Madison County, ILIL263,110348−4%

09Rock Island County, ILIL141,869348−0%

10McHenry County, ILIL317,751304−30%

11Peoria County, ILIL178,553296−0%

12Sangamon County, ILIL194,170205−6%

13Macon County, ILIL99,300202+2%

14Tazewell County, ILIL130,049191−4%

15Champaign County, ILIL209,972174−4%

16Kankakee County, ILIL105,525142−7%

17Williamson County, ILIL67,225137−6%

18DeKalb County, ILIL101,835123−12%

19Kendall County, ILIL145,470123−28%

20Boone County, ILIL53,568110−26%

21McLean County, ILIL171,419109−14%

22Jackson County, ILIL52,501105+2%

23Coles County, ILIL46,607102−3%

24Franklin County, ILIL36,91699+3%

25Vermilion County, ILIL71,25998+5%

26LaSalle County, ILIL107,77394−4%

27Whiteside County, ILIL54,12188−1%

28Stephenson County, ILIL43,22085−2%

29Knox County, ILIL47,76779+1%

30Grundy County, ILIL54,05277−14%

31Adams County, ILIL64,26777−3%

32Marion County, ILIL36,38273−0%

33Clinton County, ILIL37,12872−4%

34Saline County, ILIL22,77270−1%

35Effingham County, ILIL34,51966−7%

36Jefferson County, ILIL36,14765−8%

37Morgan County, ILIL32,51564−1%

38Massac County, ILIL13,50262−3%

39Henry County, ILIL48,09562+0%

40Woodford County, ILIL38,11162−8%

41Ogle County, ILIL51,39961−10%

42Randolph County, ILIL29,92160+2%

43McDonough County, ILIL25,91660+7%

44Wabash County, ILIL10,90759+1%

45Monroe County, ILIL34,84058−19%

46Jersey County, ILIL21,16056−5%

47Macoupin County, ILIL43,74855−3%

48Logan County, ILIL27,18250−1%

49Christian County, ILIL33,44349−3%

50Perry County, ILIL20,16048−7%

51Lee County, ILIL32,91447−5%

52Douglas County, ILIL19,88047−2%

53Richland County, ILIL15,21946+2%

54Alexander County, ILIL4,57045+11%

55Fulton County, ILIL32,90144−0%

56Crawford County, ILIL18,64844−5%

57Montgomery County, ILIL28,07644+0%

58Lawrence County, ILIL13,79043+3%

59Union County, ILIL16,65643−4%

60De Witt County, ILIL15,11842−2%

61Moultrie County, ILIL14,37141−2%

62Bureau County, ILIL32,51041+1%

63Bond County, ILIL16,95939−15%

64Pulaski County, ILIL4,82038+2%

65Carroll County, ILIL15,41938+1%

66Livingston County, ILIL35,05738−1%

67Jo Daviess County, ILIL21,59436−2%

68Putnam County, ILIL5,61936−6%

69Cass County, ILIL12,46336−2%

70Menard County, ILIL11,86336−11%

71Piatt County, ILIL16,79135−5%

72Warren County, ILIL16,22235+2%

73Edwards County, ILIL5,89833+7%

74White County, ILIL13,25033+7%

75Marshall County, ILIL11,47333−3%

76Johnson County, ILIL13,36333−12%

77Clark County, ILIL15,11432−6%

78Edgar County, ILIL16,32331−1%

79Clay County, ILIL12,79331−1%

80Cumberland County, ILIL10,20831−5%

81Mercer County, ILIL15,22931+2%

82Mason County, ILIL12,41130+1%

83Ford County, ILIL13,21629+0%

84Shelby County, ILIL20,57629−3%

85Hardin County, ILIL3,58829+8%

86Fayette County, ILIL20,79029−4%

87Greene County, ILIL11,31328+4%

88Iroquois County, ILIL26,15028−2%

89Hancock County, ILIL16,80327+6%

90Washington County, ILIL13,56427−1%

91Wayne County, ILIL15,88224+1%

92Stark County, ILIL5,31923+3%

93Scott County, ILIL4,86623+2%

94Jasper County, ILIL9,03221+5%

95Gallatin County, ILIL4,61621+7%

96Henderson County, ILIL5,98421−1%

97Pike County, ILIL14,23121+1%

98Calhoun County, ILIL4,30021+5%

99Hamilton County, ILIL7,85920−1%

100Brown County, ILIL6,40119−16%

101Schuyler County, ILIL6,65717+4%

102Pope County, ILIL3,67212−1%

SHOWING 1–102 OF 102

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UPDATED 2026-06-02 · DATA: US CENSUS BUREAU ACS 5-YEAR ESTIMATES