RANKING · 2020 CENSUS · 88 SHOWN OF 88

Largest by population, Ohio counties · 2020

The most populous Ohio counties as of the 2020 population estimates. This list covers the 88 counties in Ohio that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros ZIP codes

RELATEDFastest growing Fastest shrinking Most population gained Most population lost Most densely populated Most sparsely populated

YEAR1990 2000 2010 2020 2025

RANKPLACESTATETOTAL POPULATIONVS 2000

01Franklin County, OHOH1,323,807+24%

02Cuyahoga County, OHOH1,264,817−9%

03Hamilton County, OHOH830,639−2%

04Summit County, OHOH540,428−0%

05Montgomery County, OHOH537,309−4%

06Lucas County, OHOH431,279−5%

07Butler County, OHOH390,357+17%

08Stark County, OHOH374,853−1%

09Lorain County, OHOH312,964+10%

10Warren County, OHOH242,337+53%

11Lake County, OHOH232,603+2%

12Mahoning County, OHOH228,614−11%

13Delaware County, OHOH214,124+95%

14Clermont County, OHOH208,601+17%

15Trumbull County, OHOH201,977−10%

16Medina County, OHOH182,470+21%

17Licking County, OHOH178,519+23%

18Greene County, OHOH167,966+14%

19Portage County, OHOH161,791+6%

20Fairfield County, OHOH158,921+29%

21Clark County, OHOH136,001−6%

22Wood County, OHOH132,248+9%

23Richland County, OHOH124,936−3%

24Wayne County, OHOH116,894+5%

25Miami County, OHOH108,774+10%

26Allen County, OHOH102,206−6%

27Columbiana County, OHOH101,877−9%

28Ashtabula County, OHOH97,574−5%

29Geauga County, OHOH95,397+5%

30Tuscarawas County, OHOH93,263+3%

31Muskingum County, OHOH86,410+2%

32Ross County, OHOH77,093+5%

33Erie County, OHOH75,622−5%

34Hancock County, OHOH74,920+5%

35Scioto County, OHOH74,008−7%

36Belmont County, OHOH66,497−5%

37Marion County, OHOH65,359−1%

38Jefferson County, OHOH65,249−12%

39Union County, OHOH62,784+53%

40Knox County, OHOH62,721+15%

41Athens County, OHOH62,431+0%

42Washington County, OHOH59,771−6%

43Sandusky County, OHOH58,896−5%

44Huron County, OHOH58,565−2%

45Pickaway County, OHOH58,539+11%

46Lawrence County, OHOH58,240−7%

47Seneca County, OHOH55,069−6%

48Ashland County, OHOH52,447−0%

49Darke County, OHOH51,881−3%

50Shelby County, OHOH48,230+1%

51Auglaize County, OHOH46,422−0%

52Logan County, OHOH46,150+0%

53Holmes County, OHOH44,223+14%

54Madison County, OHOH43,824+9%

55Brown County, OHOH43,676+3%

56Highland County, OHOH43,317+6%

57Fulton County, OHOH42,713+1%

58Mercer County, OHOH42,528+4%

59Crawford County, OHOH42,025−11%

60Clinton County, OHOH42,018+4%

61Preble County, OHOH40,999−3%

62Ottawa County, OHOH40,364−2%

63Champaign County, OHOH38,714−0%

64Guernsey County, OHOH38,438−6%

65Defiance County, OHOH38,286−3%

66Williams County, OHOH37,102−5%

67Coshocton County, OHOH36,612−0%

68Perry County, OHOH35,408+4%

69Morrow County, OHOH34,950+11%

70Putnam County, OHOH34,451−1%

71Jackson County, OHOH32,653+0%

72Hardin County, OHOH30,696−4%

73Gallia County, OHOH29,220−6%

74Fayette County, OHOH28,951+2%

75Van Wert County, OHOH28,931−2%

76Hocking County, OHOH28,050−1%

77Henry County, OHOH27,662−5%

78Adams County, OHOH27,477+1%

79Pike County, OHOH27,088−2%

80Carroll County, OHOH26,721−7%

81Meigs County, OHOH22,210−4%

82Wyandot County, OHOH21,900−4%

83Paulding County, OHOH18,806−7%

84Harrison County, OHOH14,483−9%

85Noble County, OHOH14,115+0%

86Morgan County, OHOH13,802−7%

87Monroe County, OHOH13,385−12%

88Vinton County, OHOH12,800−0%

SHOWING 1–88 OF 88

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