Ohio population by county: July 2025 Census estimates for all 88 counties, change since 2020, density, and a link to each official parcel map.
Looking for Ohio population by county? The Census Bureau estimates that Ohio had 11,900,510 residents on July 1, 2025, spread across 88 counties. Franklin County is the most populous, with 1,361,536 people (11% of the state), and Vinton County is the least populous, with 12,645.
The table below lists every county with its 2025 estimate, its April 2020 starting point, the change, people per square mile, and a link to its official parcel viewer.
Percent change runs from the April 1, 2020 estimates base to July 1, 2025. People per square mile is the July 2025 estimate divided by the county's land area in the Census Bureau's 2020 Gazetteer file, so lakes and bays are left out.
How Ohio's population is spread out
Grouping the counties by size shows how concentrated the state is:
Residents (July 2025)
Counties
Total residents
Share of state
1,000,000 or more
2
2,594,461
22%
250,000 to 999,999
8
3,694,038
31%
100,000 to 249,999
16
2,717,653
23%
25,000 to 99,999
54
2,764,866
23%
10,000 to 24,999
8
129,492
1%
10 counties with at least 250,000 residents hold 53% of the state's population.
Most and least densely populated
The most crowded counties by people per square mile of land:
Cuyahoga County: 2,697 per sq mi (1,232,925 people on 457 sq mi)
Franklin County: 2,557 per sq mi (1,361,536 people on 532 sq mi)
Hamilton County: 2,068 per sq mi (838,418 people on 405 sq mi)
Summit County: 1,304 per sq mi (538,376 people on 413 sq mi)
Lucas County: 1,246 per sq mi (423,347 people on 340 sq mi)
The most thinly settled:
Monroe County: 29 per sq mi (12,994 people on 456 sq mi)
Vinton County: 31 per sq mi (12,645 people on 412 sq mi)
Morgan County: 33 per sq mi (13,626 people on 416 sq mi)
Harrison County: 35 per sq mi (14,070 people on 402 sq mi)
Noble County: 36 per sq mi (14,276 people on 398 sq mi)
About these numbers
They are estimates. Between censuses the Census Bureau's Population Estimates Program updates county totals each year from births, deaths and migration records. The next full count is the 2030 census.
The base is April 1, 2020. The estimates start from an April 1, 2020 "estimates base" built from the 2020 census, which is why it is slightly different from the published census count.
Each new release revises the past. A newer vintage can change earlier years as well, so compare numbers from the same release, as this page does.
Statewide total. The counties add up exactly to the statewide figure of 11,900,510 in the same file.
Using population numbers in a land search
Big counties, busy offices. In the most populous counties, parcel maps and deed records are usually online and searchable, but recording and permit offices are busier. Allow for that if you are on a deadline.
Small counties, fewer sales. In counties with only a few thousand people, land changes hands less often, so there are fewer recent sales to compare a price with. The county assessor's sales records are the best source.
Density hints at lot size. A low people-per-square-mile figure usually means farms, ranches and timber tracts; a high one means subdivided lots. The parcel viewer shows the actual parcel lines.
Check the official map. Use the parcel viewer link in the table for boundaries, parcel numbers and owner names, then confirm anything important with the county's recorder or assessor.