| County | Rank | Change (2020) ↓ | 2026 Pop. | 2020 Pop. |
|---|---|---|---|---|
| Union County | 1 | 18.77% | 74,909 | 63,069 |
| Delaware County | 2 | 14.88% | 247,201 | 215,181 |
| Madison County | 3 | 9.84% | 48,182 | 43,864 |
| Pickaway County | 4 | 8.68% | 63,749 | 58,659 |
| Fairfield County | 5 | 7.74% | 171,798 | 159,451 |
| Warren County | 6 | 6.62% | 259,323 | 243,211 |
| Clermont County | 7 | 5.22% | 219,640 | 208,751 |
| Greene County | 8 | 4.97% | 176,496 | 168,141 |
| Morrow County | 9 | 4.59% | 36,602 | 34,996 |
| Licking County | 10 | 4.48% | 186,788 | 178,786 |
| Miami County | 11 | 4.06% | 113,396 | 108,974 |
| Lorain County | 12 | 3.75% | 325,279 | 313,514 |
| Franklin County | 13 | 3.47% | 1,370,416 | 1,324,478 |
| Butler County | 14 | 2.98% | 402,475 | 390,845 |
| Knox County | 15 | 2.6% | 64,440 | 62,804 |
| Adams County | 16 | 2.32% | 28,088 | 27,451 |
| Wood County | 17 | 2.29% | 135,280 | 132,246 |
| Brown County | 18 | 2.17% | 44,631 | 43,684 |
| Holmes County | 19 | 2.17% | 45,197 | 44,239 |
| Coshocton County | 20 | 2.15% | 37,377 | 36,590 |
| Perry County | 21 | 1.9% | 36,131 | 35,459 |
| Medina County | 22 | 1.72% | 185,775 | 182,636 |
| Athens County | 23 | 1.49% | 63,314 | 62,386 |
| Muskingum County | 24 | 1.46% | 87,707 | 86,449 |
| Noble County | 25 | 1.35% | 14,288 | 14,098 |
| Highland County | 26 | 1.34% | 43,942 | 43,363 |
| Clinton County | 27 | 1.24% | 42,556 | 42,035 |
| Portage County | 28 | 1.08% | 163,601 | 161,853 |
| Hamilton County | 29 | 1.03% | 838,977 | 830,412 |
| Mercer County | 30 | 0.99% | 42,954 | 42,534 |
| Montgomery County | 31 | 0.96% | 542,266 | 537,115 |
| Logan County | 32 | 0.9% | 46,532 | 46,117 |
| Van Wert County | 33 | 0.82% | 29,160 | 28,922 |
| Geauga County | 34 | 0.7% | 96,052 | 95,383 |
| Jackson County | 35 | 0.68% | 32,893 | 32,671 |
| Putnam County | 36 | 0.6% | 34,600 | 34,392 |
| Crawford County | 37 | 0.57% | 42,252 | 42,013 |
| Hancock County | 38 | 0.49% | 75,307 | 74,939 |
| Champaign County | 39 | 0.47% | 38,923 | 38,741 |
| Ashland County | 40 | 0.24% | 52,611 | 52,485 |
| Henry County | 41 | 0.1% | 27,691 | 27,663 |
| Shelby County | 42 | 0.04% | 48,178 | 48,158 |
| Wayne County | 43 | 0.04% | 116,941 | 116,899 |
| Guernsey County | 44 | 0.01% | 38,429 | 38,426 |
| Summit County | 45 | 0% | 539,807 | 539,833 |
| Defiance County | 46 | -0.04% | 38,251 | 38,268 |
| Stark County | 47 | -0.05% | 374,302 | 374,476 |
| Marion County | 48 | -0.05% | 65,353 | 65,385 |
| Pike County | 49 | -0.07% | 27,046 | 27,064 |
| Lake County | 50 | -0.1% | 232,294 | 232,517 |
| Richland County | 51 | -0.11% | 124,829 | 124,969 |
| Gallia County | 52 | -0.13% | 29,188 | 29,226 |
| Ross County | 53 | -0.27% | 76,860 | 77,067 |
| Huron County | 54 | -0.37% | 58,272 | 58,487 |
| Sandusky County | 55 | -0.38% | 58,659 | 58,880 |
| Vinton County | 56 | -0.55% | 12,733 | 12,803 |
| Darke County | 57 | -0.59% | 51,595 | 51,901 |
| Paulding County | 58 | -0.6% | 18,697 | 18,809 |
| Tuscarawas County | 59 | -0.74% | 92,514 | 93,205 |
| Morgan County | 60 | -0.79% | 13,647 | 13,756 |
| Ashtabula County | 61 | -0.84% | 96,678 | 97,497 |
| Preble County | 62 | -0.97% | 40,610 | 41,007 |
| Clark County | 63 | -1.01% | 134,510 | 135,888 |
| Auglaize County | 64 | -1.26% | 45,882 | 46,466 |
| Allen County | 65 | -1.28% | 100,810 | 102,116 |
| Seneca County | 66 | -1.29% | 54,350 | 55,061 |
| Wyandot County | 67 | -1.38% | 21,575 | 21,878 |
| Carroll County | 68 | -1.41% | 26,383 | 26,761 |
| Mahoning County | 69 | -1.48% | 224,635 | 228,006 |
| Williams County | 70 | -1.64% | 36,477 | 37,084 |
| Hocking County | 71 | -1.7% | 27,564 | 28,040 |
| Trumbull County | 72 | -1.75% | 198,130 | 201,664 |
| Lucas County | 73 | -1.95% | 422,439 | 430,831 |
| Fayette County | 74 | -1.98% | 28,395 | 28,969 |
| Fulton County | 75 | -2.38% | 41,631 | 42,647 |
| Cuyahoga County | 76 | -2.41% | 1,232,236 | 1,262,619 |
| Washington County | 77 | -2.48% | 58,179 | 59,657 |
| Meigs County | 78 | -2.51% | 21,612 | 22,168 |
| Columbiana County | 79 | -2.54% | 99,078 | 101,661 |
| Ottawa County | 80 | -2.65% | 39,233 | 40,303 |
| Hardin County | 81 | -2.71% | 29,890 | 30,724 |
| Jefferson County | 82 | -2.81% | 63,326 | 65,159 |
| Harrison County | 83 | -3.15% | 14,041 | 14,498 |
| Monroe County | 84 | -3.21% | 12,921 | 13,350 |
| Belmont County | 85 | -3.29% | 64,104 | 66,285 |
| Erie County | 86 | -3.34% | 72,947 | 75,471 |
| Scioto County | 87 | -3.99% | 70,906 | 73,849 |
| Lawrence County | 88 | -4.61% | 55,463 | 58,146 |
Ohio's counties show varied growth patterns from 2020 to 2026. Union County leads with 2.91% annualized growth, followed by Delaware County (2.34%) and Madison County (1.58%). The largest counties are Franklin County (1,370,416), Cuyahoga County (1,232,236), and Hamilton County (838,977). Of the 88 counties in Ohio, 44 are growing while 44 have experienced population decline. Overall, counties averaged 0.12% annualized growth, with total population growing by 0.2% annually.
-0.05
-0.025
0
0.025
0.05
0.075