Fastest Growing Counties in Ohio (2025)

County
Rank
Change (2020)
2025 Pop.
2020 Pop.
Union County119.14%75,15963,085
Delaware County212.4%241,856215,166
Pickaway County37.82%63,24458,656
Fairfield County46.72%170,168159,448
Madison County56.37%46,64443,849
Athens County66.35%66,35662,393
Warren County75.65%256,974243,228
Licking County84.08%186,073178,784
Morrow County93.24%36,11334,980
Miami County102.98%112,202108,959
Clermont County112.78%214,558208,750
Lorain County122.61%321,668313,498
Butler County132.25%399,673390,878
Coshocton County142.17%37,37736,584
Wood County151.82%134,666132,256
Greene County161.72%171,019168,131
Portage County171.64%164,511161,853
Highland County181.46%43,99043,359
Medina County191.37%185,148182,646
Noble County201.37%14,28314,090
Knox County211.22%63,56862,803
Defiance County221.12%38,68938,262
Champaign County230.79%39,04938,743
Franklin County240.78%1,334,7291,324,441
Carroll County250.75%26,90226,702
Perry County260.75%35,71135,446
Adams County270.75%27,64527,440
Brown County280.59%43,93143,673
Holmes County290.41%44,40844,227
Muskingum County300.25%86,68786,468
Sandusky County310.23%58,99358,856
Hamilton County320.16%831,732830,377
Ashland County330.1%52,52252,470
Clinton County340.01%42,03442,028
Marion County35-0.08%65,33565,388
Logan County36-0.15%46,04746,116
Geauga County37-0.16%95,23995,387
Mercer County38-0.17%42,46942,542
Jackson County39-0.2%32,59632,662
Richland County40-0.24%124,670124,966
Pike County41-0.34%26,97927,072
Wayne County42-0.43%116,426116,923
Shelby County43-0.45%47,92748,146
Lake County44-0.46%231,448232,516
Auglaize County45-0.46%46,25846,472
Hancock County46-0.49%74,56474,928
Montgomery County47-0.5%534,440537,119
Stark County48-0.52%372,578374,522
Huron County49-0.57%58,15958,495
Henry County50-0.58%27,50827,668
Fayette County51-0.65%28,78728,975
Guernsey County52-0.72%38,14738,423
Ross County53-0.73%76,48777,049
Summit County54-0.77%535,661539,821
Ashtabula County55-0.9%96,61597,495
Seneca County56-0.98%54,51355,054
Trumbull County57-1%199,667201,681
Crawford County58-1.06%41,56942,013
Clark County59-1.12%134,366135,887
Gallia County60-1.15%28,89829,233
Paulding County61-1.15%18,59418,811
Morgan County62-1.18%13,60013,762
Preble County63-1.19%40,52041,007
Putnam County64-1.3%33,93734,385
Hardin County65-1.32%30,32230,727
Mahoning County66-1.34%224,944228,009
Darke County67-1.35%51,19351,893
Van Wert County68-1.42%28,50428,916
Williams County69-1.62%36,47737,078
Tuscarawas County70-1.62%91,68093,193
Allen County71-1.77%100,320102,125
Lucas County72-1.82%423,014430,859
Ottawa County73-2.04%39,47340,296
Columbiana County74-2.2%99,408101,642
Fulton County75-2.21%41,70542,646
Monroe County76-2.4%13,02913,350
Jefferson County77-2.53%63,53265,178
Wyandot County78-2.73%21,26721,864
Washington County79-2.77%57,99559,647
Cuyahoga County80-2.95%1,225,2761,262,573
Scioto County81-3.14%71,52973,848
Erie County82-3.18%73,07775,481
Meigs County83-3.52%21,37922,159
Hocking County84-3.77%26,98428,040
Belmont County85-3.81%63,76466,292
Vinton County86-4.16%12,26812,801
Harrison County87-4.94%13,77514,491
Lawrence County88-5.03%55,21058,137

Ohio County Growth Overview

Ohio's counties show varied growth patterns from 2020 to 2025. Union County leads with 19.14% annualized growth, followed by Delaware County (12.4%) and Pickaway County (7.82%). The largest counties are Franklin County (1,334,729), Cuyahoga County (1,225,276), and Hamilton County (831,732). Of the 88 counties in Ohio, 34 are growing while 54 have experienced population decline. Overall, counties averaged 0.21% annualized growth, with total population growing by 0.34% annually.