What are the fastest-growing counties in Ohio?
Union County is the fastest-growing county in Ohio: its population grew 3.09% a year from 2020 to 2025, to 73,446 residents (Census PEP Vintage 2025). Delaware County (2.38%) and Pickaway County (1.43%) follow. Ohio as a whole grew 0.17% a year to 11,900,510 residents.
Data as of 2026-09-23. Population, growth and migration: PEP Vintage 2025 · 2020–2025. Income migration: IRS SOI 2022–2023 (2-yr lag).
Top 10 counties in Ohio by population growth, 2020 to 2025
| Rank | County | Population | Growth (% per year) | Net domestic migration | Net international migration | IRS net AGI migration |
|---|---|---|---|---|---|---|
| 1 | Union County | 73,446 | 3.09% | +8,271 | +732 | +$92.4M |
| 2 | Delaware County | 242,032 | 2.38% | +19,736 | +4,419 | +$185.3M |
| 3 | Pickaway County | 62,978 | 1.43% | +4,468 | +66 | +$28.1M |
| 4 | Madison County | 46,985 | 1.38% | +3,100 | +189 | +$25.6M |
| 5 | Fairfield County | 169,752 | 1.26% | +8,617 | +1,722 | +$43.6M |
| 6 | Warren County | 257,181 | 1.12% | +7,737 | +5,429 | -$32.3M |
| 7 | Clermont County | 216,977 | 0.78% | +6,747 | +1,542 | +$46.9M |
| 8 | Licking County | 185,564 | 0.75% | +6,138 | +1,115 | +$19.7M |
| 9 | Morrow County | 36,305 | 0.74% | +1,279 | +28 | +$18.5M |
| 10 | Greene County | 174,322 | 0.72% | +4,751 | +1,765 | -$20.8M |
Where are people moving in Ohio?
Delaware County gained the most people from elsewhere in the United States: net domestic migration of +19,736 from 2020 to 2025 (Census PEP Vintage 2025). The table ranks every Ohio place with 10,000 or more residents by that figure; the IRS column shows net adjusted gross income migration for 2022 to 2023.
| Rank | County | Population | Growth (% per year) | Net domestic migration | Net international migration | IRS net AGI migration |
|---|---|---|---|---|---|---|
| 1 | Delaware County | 242,032 | 2.38% | +19,736 | +4,419 | +$185.3M |
| 2 | Lorain County | 323,219 | 0.61% | +10,628 | +1,852 | +$60.2M |
| 3 | Fairfield County | 169,752 | 1.26% | +8,617 | +1,722 | +$43.6M |
| 4 | Union County | 73,446 | 3.09% | +8,271 | +732 | +$92.4M |
| 5 | Warren County | 257,181 | 1.12% | +7,737 | +5,429 | -$32.3M |
| 6 | Clermont County | 216,977 | 0.78% | +6,747 | +1,542 | +$46.9M |
| 7 | Licking County | 185,564 | 0.75% | +6,138 | +1,115 | +$19.7M |
| 8 | Greene County | 174,322 | 0.72% | +4,751 | +1,765 | -$20.8M |
| 9 | Pickaway County | 62,978 | 1.43% | +4,468 | +66 | +$28.1M |
| 10 | Miami County | 112,634 | 0.66% | +3,945 | +601 | +$18.0M |
Go past the headline numbers
The interactive Demographics map layer and the full report for a single place are part of paid plans.
Get the Demographics Report for Union CountyFrequently asked questions
- What are the fastest-growing counties in Ohio?
- By population growth from 2020 to 2025, the fastest are Union County (3.09% a year), Delaware County (2.38% a year), Pickaway County (1.43% a year), Madison County (1.38% a year) and Fairfield County (1.26% a year) (Census PEP Vintage 2025). Only places with 10,000 or more residents are ranked.
- Where are people moving in Ohio?
- By net domestic migration from 2020 to 2025, the largest gains are Delaware County (+19,736), Lorain County (+10,628) and Fairfield County (+8,617) (Census PEP Vintage 2025).
- How fast is Ohio growing overall?
- Ohio grew 0.17% a year from 2020 to 2025, to 11,900,510 residents, with net migration of +148,703 people (Census PEP Vintage 2025).
- Where does this Ohio data come from, and how current is it?
- Population, growth and migration come from the U.S. Census Bureau Population Estimates Program (PEP Vintage 2025 · 2020–2025). Income migration comes from IRS Statistics of Income (IRS SOI 2022–2023 (2-yr lag)). Counties with fewer than 10,000 residents are not ranked. Data last loaded 2026-09-23.
Data as of 2026-09-23: sources and periods
- Population, growth and migration
- U.S. Census Bureau, Population Estimates Program: PEP Vintage 2025 · 2020–2025. census.gov/programs-surveys/popest
- Income migration (net AGI)
- Internal Revenue Service, Statistics of Income migration data: IRS SOI 2022–2023 (2-yr lag). irs.gov/statistics/soi-tax-stats-migration-data
How to read the table
- Population is the Census July 1 estimate of the latest vintage.
- Growth is the compound annual rate over 2020 to 2025.
- Net domestic and international migration are cumulative people over 2020 to 2025.
- IRS net AGI migration is adjusted gross income that moved in, less what moved out, for 2022 to 2023. A plus sign means a net inflow.
- Places with fewer than 10,000 residents are left out of the rankings.