# Counties in Ohio by population under 18, 2025

All 88 values come from U.S. Census Bureau for 2025, so the places are comparable.

- Indicator id: `population_0_17_share`
- Unit: %
- Definition: Residents aged 0 to 17 as a percentage of total population on 1 July. United States: Census Bureau county population estimates by age; states and the nation are sums of their counties.
- Source: U.S. Census Bureau, Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties (https://www.census.gov/programs-surveys/popest/data/data-sets.html)
- Retrieved: 2026-10-12
- Citation: U.S. Census Bureau. Population Estimates Program, county population by age and sex: residents aged 0 to 17 as a percentage of the total on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage; states and the nation summed from counties. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
- Web page: https://invokely.ai/rankings/population-under-18/ohio-counties

| Rank | Place | % |
|---:|---|---:|
| 1 | Holmes County | 30.2 |
| 2 | Mercer County | 25.7 |
| 3 | Putnam County | 24.9 |
| 4 | Union County | 24 |
| 5 | Shelby County | 24 |
| 6 | Coshocton County | 23.8 |
| 7 | Adams County | 23.7 |
| 8 | Delaware County | 23.7 |
| 9 | Jackson County | 23.4 |
| 10 | Pike County | 23.4 |
| 11 | Highland County | 23.4 |
| 12 | Fairfield County | 23.4 |
| 13 | Perry County | 23.2 |
| 14 | Gallia County | 23.1 |
| 15 | Hardin County | 23 |
| 16 | Wayne County | 23 |
| 17 | Warren County | 23 |
| 18 | Darke County | 23 |
| 19 | Van Wert County | 22.9 |
| 20 | Paulding County | 22.7 |
| 21 | Allen County | 22.7 |
| 22 | Auglaize County | 22.7 |
| 23 | Tuscarawas County | 22.6 |
| 24 | Henry County | 22.5 |
| 25 | Franklin County | 22.5 |
| 26 | Brown County | 22.4 |
| 27 | Fayette County | 22.4 |
| 28 | Miami County | 22.4 |
| 29 | Knox County | 22.3 |
| 30 | Huron County | 22.3 |
| 31 | Muskingum County | 22.3 |
| 32 | Defiance County | 22.3 |
| 33 | Butler County | 22.2 |
| 34 | Vinton County | 22.1 |
| 35 | Licking County | 22.1 |
| 36 | Ashland County | 22 |
| 37 | Fulton County | 22 |
| 38 | Guernsey County | 22 |
| 39 | Hamilton County | 21.9 |
| 40 | Clark County | 21.9 |
| 41 | Morrow County | 21.8 |
| 42 | Logan County | 21.8 |
| 43 | Pickaway County | 21.8 |
| 44 | Lucas County | 21.7 |
| 45 | Clinton County | 21.7 |
| 46 | Champaign County | 21.6 |
| 47 | Wyandot County | 21.5 |
| 48 | Preble County | 21.5 |
| 49 | Montgomery County | 21.5 |
| 50 | Geauga County | 21.4 |
| 51 | Marion County | 21.4 |
| 52 | Williams County | 21.3 |
| 53 | Scioto County | 21.3 |
| 54 | Hancock County | 21.3 |
| 55 | Clermont County | 21.2 |
| 56 | Ashtabula County | 21.1 |
| 57 | Crawford County | 21 |
| 58 | Sandusky County | 20.9 |
| 59 | Lawrence County | 20.9 |
| 60 | Stark County | 20.9 |
| 61 | Richland County | 20.9 |
| 62 | Harrison County | 20.9 |
| 63 | Seneca County | 20.9 |
| 64 | Morgan County | 20.8 |
| 65 | Lorain County | 20.7 |
| 66 | Hocking County | 20.6 |
| 67 | Carroll County | 20.5 |
| 68 | Medina County | 20.4 |
| 69 | Ross County | 20.3 |
| 70 | Greene County | 20.3 |
| 71 | Meigs County | 20.2 |
| 72 | Summit County | 20 |
| 73 | Madison County | 19.9 |
| 74 | Trumbull County | 19.7 |
| 75 | Monroe County | 19.7 |
| 76 | Mahoning County | 19.6 |
| 77 | Cuyahoga County | 19.6 |
| 77 | Wood County | 19.6 |
| 79 | Columbiana County | 19.5 |
| 80 | Jefferson County | 19.3 |
| 81 | Washington County | 19.2 |
| 82 | Noble County | 18.6 |
| 83 | Erie County | 18.6 |
| 84 | Belmont County | 18.2 |
| 85 | Lake County | 18.2 |
| 86 | Portage County | 17.4 |
| 87 | Ottawa County | 16.8 |
| 88 | Athens County | 14.6 |