PlainCities

Counties · Ohio

Counties of Ohio

Ohio has 88 counties. Franklin County is the largest with 1,361,536 residents in 2025. 39 of the 88 gained residents between 2020 and 2025 by the Census Bureau's estimates.

What counties are in Ohio?

Sorted by the 2025 population estimate; sort by any column.

Counties of Ohio: 2025 estimate, change since 2020, ACS 2020-2024 5-year estimates
Franklin County1,361,536+2.9%48328$75,176$288,400
Cuyahoga County1,232,925−2.5%59428$64,468$195,400
Hamilton County838,418+0.9%101226$72,470$241,900
Montgomery County539,598+0.4%34156$66,139$180,900
Summit County538,376−0.4%36138$71,622$208,700
Lucas County423,347−1.8%25169$62,224$163,900
Butler County400,128+2.5%3486$81,590$258,500
Stark County373,771−0.3%4890$67,934$186,400
Lorain County323,219+3.3%3680$73,347$223,200
Warren County257,181+6.1%3444$110,132$349,400
Delaware County242,032+13.0%3140$133,540$445,500
Lake County232,217−0.1%2360$80,925$214,100
Mahoning County224,706−1.7%4075$56,942$154,700
Clermont County216,977+4.0%3548$85,510$266,200
Trumbull County198,972−1.5%5254$56,435$141,800
Licking County185,564+4.0%4946$84,426$275,200
Medina County185,025+1.4%3142$94,968$287,000
Greene County174,322+3.8%2842$87,309$252,200
Fairfield County169,752+6.8%3536$90,966$298,800
Portage County163,404+1.0%3338$75,766$227,000
Clark County135,340−0.5%2745$63,132$169,900
Wood County134,176+1.5%4731$74,216$227,600
Richland County124,893−0.0%3130$59,509$164,800
Wayne County116,758−0.1%3532$73,574$222,100
Miami County112,634+3.5%2723$76,817$229,100
Allen County100,881−1.3%2435$64,038$165,300
Columbiana County99,377−2.5%4225$58,180$151,600
Ashtabula County96,713−0.9%4129$57,728$159,500
Geauga County95,676+0.3%2621$107,860$331,100
Tuscarawas County92,373−1.0%4424$65,044$185,400
Muskingum County87,014+0.7%4221$60,780$182,200
Ross County76,429−0.9%2817$61,303$171,500
Hancock County75,034+0.1%3015$73,141$204,700
Union County73,446+17.0%2413$112,322$344,900
Erie County73,296−3.1%2420$71,993$199,700
Scioto County71,365−3.6%3121$50,609$137,900
Marion County65,115−0.4%2318$59,371$156,800
Belmont County64,434−3.1%4022$57,017$154,900
Knox County64,002+2.0%3414$73,878$239,400
Jefferson County63,597−2.5%3622$59,055$127,800
Athens County63,197+1.2%2915$56,001$185,000
Pickaway County62,978+7.6%2816$74,040$256,800
Sandusky County58,655−0.4%2815$62,295$160,700
Washington County58,389−2.3%3518$63,603$185,600
Huron County58,250−0.5%3313$67,878$166,000
Lawrence County55,710−4.3%2318$58,325$144,000
Seneca County54,522−1.0%3014$66,025$154,700
Ashland County52,523+0.1%2712$69,860$186,800
Darke County51,520−0.7%4114$64,486$173,200
Shelby County48,065−0.4%2510$73,978$208,100
Madison County46,985+7.1%2312$87,045$250,100
Logan County46,302+0.3%3311$71,551$203,200
Auglaize County45,909−1.1%2511$78,660$189,800
Holmes County44,970+1.7%2610$76,140$267,700
Brown County44,397+1.6%2810$71,270$196,200
Highland County43,823+1.2%2811$65,785$168,900
Mercer County42,737+0.5%249$76,782$210,600
Clinton County42,301+0.7%2210$70,407$211,900
Crawford County41,896−0.3%2513$58,044$136,700
Fulton County41,853−2.0%2210$72,864$191,000
Preble County40,664−0.8%2312$69,223$180,900
Ottawa County39,481−2.2%2315$76,101$219,900
Champaign County38,820+0.3%2010$75,556$204,000
Guernsey County38,379−0.2%3110$58,478$157,700
Defiance County38,292+0.0%179$73,064$163,200
Coshocton County37,188+1.6%3110$55,577$155,500
Williams County36,549−1.5%269$61,048$150,000
Morrow County36,305+3.9%279$75,283$222,300
Perry County35,918+1.4%289$67,460$191,100
Putnam County34,380−0.2%318$84,928$201,100
Jackson County32,817+0.5%167$57,106$150,700
Hardin County30,072−2.0%258$62,484$151,200
Gallia County29,072−0.5%238$56,830$155,600
Van Wert County29,013+0.3%229$67,917$152,000
Fayette County28,552−1.3%187$63,275$170,700
Adams County27,865+1.4%237$50,264$164,200
Henry County27,598−0.2%237$80,099$168,600
Hocking County27,512−1.9%207$62,960$186,400
Pike County27,061−0.1%197$52,736$163,800
Carroll County26,475−1.1%237$64,835$183,100
Meigs County21,587−2.8%186$46,873$119,300
Wyandot County21,567−1.6%226$69,768$163,400
Paulding County18,727−0.4%235$67,731$140,800
Noble County14,276+1.2%214$56,098$163,600
Harrison County14,070−2.9%265$54,414$121,500
Morgan County13,626−1.3%194$59,351$150,900
Monroe County12,994−2.9%304$60,134$142,700
Vinton County12,645−1.2%163$55,336$150,000

Source: PEP Vintage 2025 (CO-EST2025); American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) · Census population estimates

How these figures are made: methodology and release checks · reading a margin of error · every state · corrections