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. The median across all 88 is 58,389. Biggest climber in the top 100 since 2020: Union County, OH, up 5 places to #34.

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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%

04▲1Montgomery County, OHOH539,598−3%

05▼1Summit 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%

11▲2Delaware County, OHOH242,032+120%

12▼1Lake County, OHOH232,217+2%

13▼1Mahoning County, OHOH224,706−13%

14Clermont County, OHOH216,977+22%

15Trumbull County, OHOH198,972−12%

16▲1Licking County, OHOH185,564+28%

17▼1Medina County, OHOH185,025+22%

18Greene County, OHOH174,322+18%

19▲1Fairfield County, OHOH169,752+38%

20▼1Portage 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%

33▲1Hancock County, OHOH75,034+5%

34▲5Union County, OHOH73,446+80%

35▼2Erie County, OHOH73,296−8%

36▼1Scioto County, OHOH71,365−10%

37Marion County, OHOH65,115−2%

38▼2Belmont County, OHOH64,434−8%

39▲1Knox County, OHOH64,002+17%

40▼2Jefferson County, OHOH63,597−14%

41Athens County, OHOH63,197+2%

42▲3Pickaway County, OHOH62,978+19%

43Sandusky County, OHOH58,655−5%

44▼2Washington County, OHOH58,389−8%

45▼1Huron County, OHOH58,250−2%

46Lawrence County, OHOH55,710−11%

47Seneca County, OHOH54,522−7%

48Ashland County, OHOH52,5230%

49Darke County, OHOH51,520−3%

50Shelby County, OHOH48,0650%

51▲3Madison County, OHOH46,985+17%

52Logan County, OHOH46,302+1%

53▼2Auglaize County, OHOH45,909−2%

54▼1Holmes County, OHOH44,970+15%

55Brown County, OHOH44,397+5%

56Highland County, OHOH43,823+7%

57▲1Mercer County, OHOH42,737+4%

58▲2Clinton County, OHOH42,301+4%

59Crawford County, OHOH41,896−11%

60▼3Fulton County, OHOH41,853−1%

61Preble County, OHOH40,664−4%

62Ottawa County, OHOH39,481−4%

63Champaign County, OHOH38,8200%

64Guernsey County, OHOH38,379−6%

65Defiance County, OHOH38,292−3%

66▲1Coshocton County, OHOH37,188+1%

67▼1Williams County, OHOH36,549−7%

68▲1Morrow County, OHOH36,305+15%

69▼1Perry County, OHOH35,918+5%

70Putnam County, OHOH34,380−1%

71Jackson County, OHOH32,817+1%

72Hardin County, OHOH30,072−6%

73Gallia County, OHOH29,072−6%

74▲1Van Wert County, OHOH29,013−2%

75▼1Fayette County, OHOH28,5520%

76▲2Adams County, OHOH27,865+2%

77Henry County, OHOH27,598−6%

78▼2Hocking 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%

84▲1Noble County, OHOH14,276+2%

85▼1Harrison 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 2026-09-11 · DATA: US CENSUS BUREAU POPULATION ESTIMATES