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%−61%

02Monroe County, ILIL34,840+6.1%−74%

03Johnson County, ILIL13,363+5.8%−57%

04Grundy County, ILIL54,052+4.9%−69%

05Will County, ILIL712,253+2.8%−93%

06Champaign County, ILIL209,972+2.4%−38%

07Carroll County, ILIL15,419+2.0%−363%

08DuPage County, ILIL934,298+1.7%−89%

09Cook County, ILIL5,194,625+1.6%−71%

10Lake County, ILIL719,339+1.5%−94%

11Effingham County, ILIL34,519+1.2%−85%

12Williamson County, ILIL67,225+1.2%−81%

13McLean County, ILIL171,419+0.8%−95%

14McHenry County, ILIL317,751+0.5%−99%

15Kane County, ILIL525,757+0.2%−99%

16Piatt County, ILIL16,791-0.3%−106%

17Woodford County, ILIL38,111-0.5%−106%

18Sangamon County, ILIL194,170-0.6%−110%

19Douglas County, ILIL19,880-1.2%−151%

20Madison County, ILIL263,110-1.3%−133%

21Boone County, ILIL53,568-1.3%−104%

22Rock Island County, ILIL141,869-1.9%−545%

23Adams County, ILIL64,267-2.0%−162%

24Moultrie County, ILIL14,371-2.2%−184%

25Christian County, ILIL33,443-2.2%−180%

26Clinton County, ILIL37,128-2.3%−149%

27Henry County, ILIL48,095-2.4%+776%

28Peoria County, ILIL178,553-2.5%−855%

29Richland County, ILIL15,219-2.6%+8%

30Jo Daviess County, ILIL21,594-2.8%−232%

31Fayette County, ILIL20,790-2.9%−168%

32Tazewell County, ILIL130,049-3.0%−177%

33Union County, ILIL16,656-3.2%−183%

34Ogle County, ILIL51,399-3.2%−129%

35Menard County, ILIL11,863-3.2%−127%

36Winnebago County, ILIL283,674-3.4%−133%

37Wayne County, ILIL15,882-3.5%+564%

38LaSalle County, ILIL107,773-3.7%−187%

39Clay County, ILIL12,793-3.8%−652%

40Ford County, ILIL13,216-3.9%+1531%

41Jasper County, ILIL9,032-4.2%−9%

42Marion County, ILIL36,382-4.3%−1485%

43Cass County, ILIL12,463-4.4%−329%

44Jefferson County, ILIL36,147-4.4%−154%

45Franklin County, ILIL36,916-4.4%+38%

46Mercer County, ILIL15,229-4.5%+132%

47DeKalb County, ILIL101,835-4.5%−132%

48Saline County, ILIL22,772-4.6%−770%

49St. Clair County, ILIL250,708-4.7%+82%

50Whiteside County, ILIL54,121-4.8%−718%

51Wabash County, ILIL10,907-4.9%+270%

52Warren County, ILIL16,222-4.9%+112%

53Bureau County, ILIL32,510-5.0%+856%

54Lee County, ILIL32,914-5.2%−208%

55Kankakee County, ILIL105,525-5.2%−167%

56White County, ILIL13,250-5.4%−23%

57Clark County, ILIL15,114-5.4%−179%

58Cumberland County, ILIL10,208-5.4%−199%

59Hamilton County, ILIL7,859-5.5%−482%

60Knox County, ILIL47,767-5.6%+465%

61Crawford County, ILIL18,648-5.7%−213%

62Macoupin County, ILIL43,748-5.9%−308%

63Bond County, ILIL16,959-5.9%−133%

64Montgomery County, ILIL28,076-6.0%+2339%

65Macon County, ILIL99,300-6.1%+187%

66Shelby County, ILIL20,576-6.1%−316%

67Putnam County, ILIL5,619-6.1%−199%

68Perry County, ILIL20,160-6.3%−180%

69De Witt County, ILIL15,118-6.3%−470%

70Jersey County, ILIL21,160-6.4%−217%

71Stephenson County, ILIL43,220-6.5%−435%

72Washington County, ILIL13,564-6.5%−631%

73Edwards County, ILIL5,898-7.1%+12%

74Marshall County, ILIL11,473-7.1%−373%

75Morgan County, ILIL32,515-7.4%−1331%

76Scott County, ILIL4,866-7.6%+300%

77Logan County, ILIL27,182-7.6%−712%

78Hancock County, ILIL16,803-7.8%+33%

79Livingston County, ILIL35,057-8.0%−939%

80Massac County, ILIL13,502-8.2%−395%

81Schuyler County, ILIL6,657-8.5%+107%

82Iroquois County, ILIL26,150-8.9%−600%

83Vermilion County, ILIL71,259-9.1%+85%

84Edgar County, ILIL16,323-9.2%−1755%

85Lawrence County, ILIL13,790-9.2%+183%

86Fulton County, ILIL32,901-9.3%−2191%

87Randolph County, ILIL29,921-9.9%+396%

88Stark County, ILIL5,319-9.9%+221%

89Brown County, ILIL6,401-10.0%−152%

90Pike County, ILIL14,231-10.3%+837%

91Mason County, ILIL12,411-10.8%+659%

92Gallatin County, ILIL4,616-11.5%+71%

93Jackson County, ILIL52,501-12.0%+405%

94Calhoun County, ILIL4,300-12.8%+186%

95Henderson County, ILIL5,984-12.9%−991%

96Coles County, ILIL46,607-13.0%−533%

97Greene County, ILIL11,313-13.7%+277%

98Hardin County, ILIL3,588-15.5%+107%

99Pulaski County, ILIL4,820-15.7%+575%

100Pope County, ILIL3,672-15.8%−1829%

101McDonough County, ILIL25,916-16.5%+149%

102Alexander County, ILIL4,570-36.4%+273%

SHOWING 1–102 OF 102

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU DECENNIAL CENSUS