Ottawa County, Ohio
County seat: Port Clinton · Population 39,481 (2025) · 255 sq mi
Ottawa County is the 62nd most populous of Ohio's 88 counties, with 39,481 people (2025 estimate). Its county seat is Port Clinton. The map shows its 8 cities and towns and the 4 neighboring counties.
Ottawa County facts
- County seat
- Port Clinton
- Population (2025 estimate)
- 39,481 −2.2% since 2020
- Land area
- 255 sq mi 86th largest of 88
- Water area
- 330 sq mi
- Population density
- 155 per sq mi
- Established
- 1840
- Named after
- Odawa indigenous people in what is known as Michigan and Ontario
- Largest city
- Port Clinton 5,875
- Median household income
- $76,101
- Cities and towns
- 8 plus 3 CDPs
- ZIP codes
- 20
- Time zone
- Eastern
- FIPS code
- 39123
Cities and towns in Ottawa County
Ottawa County has 8 incorporated cities, towns and villages. Populations count the people living inside Ottawa County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Port Clinton (county seat) | City | 5,875 | |
| Oak Harbor | Village | 2,780 | |
| Genoa | Village | 2,167 | |
| Elmore | Village | 1,370 | Sandusky County |
| Marblehead | Village | 829 | |
| Rocky Ridge | Village | 303 | |
| Clay Center | Village | 247 | |
| Put-in-Bay | Village | 152 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Curtice | 1,167 | Lucas County |
| Lakeside | 508 | |
| Williston | 287 |
ZIP codes in Ottawa County
20 ZIP codes reach into Ottawa County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 43408
- 43412 also Lucas County
- 43416 also Sandusky County
- 43420 also Sandusky County
- 43430 also Wood and Sandusky counties
- 43432
- 43433
- 43436
- 43439
- 43440
- 43442 also Sandusky County
- 43445 also Lucas County
- 43446
- 43447 also Wood County
- 43449 also Sandusky County
- 43452
- 43456
- 43458
- 43468
- 43469 also Sandusky County
Population of Ottawa County, 2020–2025
Ottawa County shrank by 886 people (−2.2%) between April 2020 and July 2025: 1,513 more deaths than births and a net gain of 627 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 40,303 |
| 2021 | 40,143 |
| 2022 | 39,945 |
| 2023 | 39,810 |
| 2024 | 39,729 |
| 2025 | 39,481 |
Neighboring counties
- Erie County southeast · 73,296 people
- Lucas County west · 423,347 people
- Sandusky County southwest · 58,655 people
- Wood County west · 134,176 people
Printable Ottawa County map
The PDF is a vector file with real text: it prints sharp on Letter paper and you can search it for a town. The PNG is 2400 pixels wide for slides and documents. Both are free to use with a credit to WhichCounty.
- PDF (Letter) (99 KB)
- PNG (2400 px) (97 KB)
Paste this code to embed the map on your site:
Sources
- Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files (1:500,000).
- Population: Census Bureau county and city estimates, Vintage 2025. CDP populations: American Community Survey 2020–2024.
- Places and ZIP codes: Census Bureau 2026 Gazetteer and 2020 ZIP Code Tabulation Area relationship files.
- County seat, founding year and name origin: Wikidata (CC0), checked against state sources.
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