RANKING · 2020 CENSUS · 102 SHOWN OF 102

Fastest growing, Illinois counties · 2020

Illinois counties ranked by population growth from the 2010 census to 2020. 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 shrinking Most population gained Most population lost Most densely populated Most sparsely populated

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION GROWTHVS 2000

01Kendall County, ILIL145,470+14.9%−23.5 pts

02Monroe County, ILIL34,840+6.1%−17.1 pts

03Johnson County, ILIL13,363+5.8%−7.7 pts

04Grundy County, ILIL54,052+4.9%−11.1 pts

05Will County, ILIL712,253+2.8%−37.8 pts

06Champaign County, ILIL209,972+2.4%−1.5 pts

07Carroll County, ILIL15,419+2.0%+2.8 pts

08DuPage County, ILIL934,298+1.7%−13.9 pts

09Cook County, ILIL5,194,625+1.6%−3.8 pts

10Lake County, ILIL719,339+1.5%−23.2 pts

11Effingham County, ILIL34,519+1.2%−6.8 pts

12Williamson County, ILIL67,225+1.2%−5.0 pts

13McLean County, ILIL171,419+0.8%−15.6 pts

14McHenry County, ILIL317,751+0.5%−41.5 pts

15Kane County, ILIL525,757+0.2%−27.1 pts

16Piatt County, ILIL16,791-0.3%−5.6 pts

17Woodford County, ILIL38,111-0.5%−9.1 pts

18Sangamon County, ILIL194,170-0.6%−6.5 pts

19Douglas County, ILIL19,880-1.2%−3.6 pts

20Madison County, ILIL263,110-1.3%−5.2 pts

21Boone County, ILIL53,568-1.3%−37.0 pts

22Rock Island County, ILIL141,869-1.9%−2.4 pts

23Adams County, ILIL64,267-2.0%−5.3 pts

24Moultrie County, ILIL14,371-2.2%−4.7 pts

25Christian County, ILIL33,443-2.2%−5.0 pts

26Clinton County, ILIL37,128-2.3%−7.0 pts

27Henry County, ILIL48,095-2.4%−2.1 pts

28Peoria County, ILIL178,553-2.5%−2.8 pts

29Richland County, ILIL15,219-2.6%−0.2 pts

30Jo Daviess County, ILIL21,594-2.8%−5.0 pts

31Fayette County, ILIL20,790-2.9%−7.3 pts

32Tazewell County, ILIL130,049-3.0%−6.9 pts

33Union County, ILIL16,656-3.2%−7.0 pts

34Ogle County, ILIL51,399-3.2%−14.2 pts

35Menard County, ILIL11,863-3.2%−15.1 pts

36Winnebago County, ILIL283,674-3.4%−13.4 pts

37Wayne County, ILIL15,882-3.5%−2.9 pts

38LaSalle County, ILIL107,773-3.7%−8.0 pts

39Clay County, ILIL12,793-3.8%−4.5 pts

40Ford County, ILIL13,216-3.9%−3.6 pts

41Jasper County, ILIL9,032-4.2%+0.4 pts

42Marion County, ILIL36,382-4.3%−4.6 pts

43Cass County, ILIL12,463-4.4%−6.3 pts

44Jefferson County, ILIL36,147-4.4%−12.6 pts

45Franklin County, ILIL36,916-4.4%−1.2 pts

46Mercer County, ILIL15,229-4.5%−2.5 pts

47DeKalb County, ILIL101,835-4.5%−18.7 pts

48Saline County, ILIL22,772-4.6%−5.3 pts

49St. Clair County, ILIL250,708-4.7%−2.1 pts

50Whiteside County, ILIL54,121-4.8%−5.6 pts

51Wabash County, ILIL10,907-4.9%−3.6 pts

52Warren County, ILIL16,222-4.9%−2.6 pts

53Bureau County, ILIL32,510-5.0%−4.4 pts

54Lee County, ILIL32,914-5.2%−10.1 pts

55Kankakee County, ILIL105,525-5.2%−13.1 pts

56White County, ILIL13,250-5.4%+1.6 pts

57Clark County, ILIL15,114-5.4%−12.2 pts

58Cumberland County, ILIL10,208-5.4%−10.9 pts

59Hamilton County, ILIL7,859-5.5%−6.9 pts

60Knox County, ILIL47,767-5.6%−4.6 pts

61Crawford County, ILIL18,648-5.7%−10.8 pts

62Macoupin County, ILIL43,748-5.9%−8.7 pts

63Bond County, ILIL16,959-5.9%−23.5 pts

64Montgomery County, ILIL28,076-6.0%−5.8 pts

65Macon County, ILIL99,300-6.1%−4.0 pts

66Shelby County, ILIL20,576-6.1%−9.0 pts

67Putnam County, ILIL5,619-6.1%−12.4 pts

68Perry County, ILIL20,160-6.3%−14.1 pts

69De Witt County, ILIL15,118-6.3%−8.0 pts

70Jersey County, ILIL21,160-6.4%−11.9 pts

71Stephenson County, ILIL43,220-6.5%−8.4 pts

72Washington County, ILIL13,564-6.5%−7.7 pts

73Edwards County, ILIL5,898-7.1%−0.8 pts

74Marshall County, ILIL11,473-7.1%−9.7 pts

75Morgan County, ILIL32,515-7.4%−8.0 pts

76Scott County, ILIL4,866-7.6%−5.7 pts

77Logan County, ILIL27,182-7.6%−8.9 pts

78Hancock County, ILIL16,803-7.8%−1.9 pts

79Livingston County, ILIL35,057-8.0%−9.0 pts

80Massac County, ILIL13,502-8.2%−10.9 pts

81Schuyler County, ILIL6,657-8.5%−4.4 pts

82Iroquois County, ILIL26,150-8.9%−10.7 pts

83Vermilion County, ILIL71,259-9.1%−4.2 pts

84Edgar County, ILIL16,323-9.2%−9.8 pts

85Lawrence County, ILIL13,790-9.2%−6.0 pts

86Fulton County, ILIL32,901-9.3%−9.8 pts

87Randolph County, ILIL29,921-9.9%−7.9 pts

88Stark County, ILIL5,319-9.9%−6.8 pts

89Brown County, ILIL6,401-10.0%−29.1 pts

90Pike County, ILIL14,231-10.3%−9.2 pts

91Mason County, ILIL12,411-10.8%−9.4 pts

92Gallatin County, ILIL4,616-11.5%−4.8 pts

93Jackson County, ILIL52,501-12.0%−9.6 pts

94Calhoun County, ILIL4,300-12.8%−8.3 pts

95Henderson County, ILIL5,984-12.9%−14.3 pts

96Coles County, ILIL46,607-13.0%−16.0 pts

97Greene County, ILIL11,313-13.7%−10.1 pts

98Hardin County, ILIL3,588-15.5%−8.0 pts

99Pulaski County, ILIL4,820-15.7%−13.4 pts

100Pope County, ILIL3,672-15.8%−16.7 pts

101McDonough County, ILIL25,916-16.5%−9.9 pts

102Alexander County, ILIL4,570-36.4%−26.6 pts

SHOWING 1–102 OF 102

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UPDATED 2026-08-08 · DATA: US CENSUS BUREAU DECENNIAL CENSUS