RANKING · 2025 ESTIMATES · 88 SHOWN OF 88

Largest by population, Ohio counties

The most populous Ohio counties as of the 2025 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, OHOH1,361,536+27%

02Cuyahoga County, OHOH1,232,925−12%

03Hamilton County, OHOH838,418−1%

04Montgomery County, OHOH539,598−3%

05Summit County, OHOH538,376−1%

06Lucas County, OHOH423,347−7%

07Butler County, OHOH400,128+20%

08Stark County, OHOH373,771−1%

09Lorain County, OHOH323,219+14%

10Warren County, OHOH257,181+62%

11Delaware County, OHOH242,032+120%

12Lake County, OHOH232,217+2%

13Mahoning County, OHOH224,706−13%

14Clermont County, OHOH216,977+22%

15Trumbull County, OHOH198,972−12%

16Licking County, OHOH185,564+28%

17Medina County, OHOH185,025+22%

18Greene County, OHOH174,322+18%

19Fairfield County, OHOH169,752+38%

20Portage County, OHOH163,404+7%

21Clark County, OHOH135,340−6%

22Wood County, OHOH134,176+11%

23Richland County, OHOH124,893−3%

24Wayne County, OHOH116,758+5%

25Miami County, OHOH112,634+14%

26Allen County, OHOH100,881−7%

27Columbiana County, OHOH99,377−11%

28Ashtabula County, OHOH96,713−6%

29Geauga County, OHOH95,676+5%

30Tuscarawas County, OHOH92,373+2%

31Muskingum County, OHOH87,014+3%

32Ross County, OHOH76,429+4%

33Hancock County, OHOH75,034+5%

34Union County, OHOH73,446+80%

35Erie County, OHOH73,296−8%

36Scioto County, OHOH71,365−10%

37Marion County, OHOH65,115−2%

38Belmont County, OHOH64,434−8%

39Knox County, OHOH64,002+17%

40Jefferson County, OHOH63,597−14%

41Athens County, OHOH63,197+2%

42Pickaway County, OHOH62,978+19%

43Sandusky County, OHOH58,655−5%

44Washington County, OHOH58,389−8%

45Huron County, OHOH58,250−2%

46Lawrence County, OHOH55,710−11%

47Seneca County, OHOH54,522−7%

48Ashland County, OHOH52,523+0%

49Darke County, OHOH51,520−3%

50Shelby County, OHOH48,065+0%

51Madison County, OHOH46,985+17%

52Logan County, OHOH46,302+1%

53Auglaize County, OHOH45,909−2%

54Holmes County, OHOH44,970+15%

55Brown County, OHOH44,397+5%

56Highland County, OHOH43,823+7%

57Mercer County, OHOH42,737+4%

58Clinton County, OHOH42,301+4%

59Crawford County, OHOH41,896−11%

60Fulton County, OHOH41,853−1%

61Preble County, OHOH40,664−4%

62Ottawa County, OHOH39,481−4%

63Champaign County, OHOH38,820−0%

64Guernsey County, OHOH38,379−6%

65Defiance County, OHOH38,292−3%

66Coshocton County, OHOH37,188+1%

67Williams County, OHOH36,549−7%

68Morrow County, OHOH36,305+15%

69Perry County, OHOH35,918+5%

70Putnam County, OHOH34,380−1%

71Jackson County, OHOH32,817+1%

72Hardin County, OHOH30,072−6%

73Gallia County, OHOH29,072−6%

74Van Wert County, OHOH29,013−2%

75Fayette County, OHOH28,552+0%

76Adams County, OHOH27,865+2%

77Henry County, OHOH27,598−6%

78Hocking County, OHOH27,512−3%

79Pike County, OHOH27,061−2%

80Carroll County, OHOH26,475−8%

81Meigs County, OHOH21,587−6%

82Wyandot County, OHOH21,567−6%

83Paulding County, OHOH18,727−8%

84Noble County, OHOH14,276+2%

85Harrison County, OHOH14,070−11%

86Morgan County, OHOH13,626−9%

87Monroe County, OHOH12,994−14%

88Vinton County, OHOH12,645−1%

SHOWING 1–88 OF 88

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU POPULATION ESTIMATES