Ottawa County, Ohio

Ottawa County is a county in Ohio, United States, on Lake Erie’s western basin about 34 miles southeast of Toledo. It had a population of 40,364 at the 2020 census, an estimated 39,994 by 2024, and covers 585 square miles (1,520 km2), of which 330 square miles is Lake Erie and Sandusky Bay, centred near 41°35′N 83°04′W.

Port Clinton is the county seat and the county’s only city; its postal code is 43452. The county holds 1 city, 7 incorporated villages and 14 unincorporated communities and census-designated places across 12 townships, and it runs on Eastern Time. Its FIPS code is 39123.

Towns & Villages in Ottawa County

Ottawa County has 22 named places on record: 1 city, 7 incorporated villages, 3 census-designated places (CDPs) and 11 unincorporated communities with no local government of their own. Many sit on peninsulas or islands reaching into Lake Erie — a geography unlike almost anywhere else in Ohio.

Two places on this list carry township ambiguity worth flagging. Williston sits near the Allen–Bay township line, and sources place it on both sides, so this page does not resolve which one its address falls under. Elmore’s village limits also cross a county line: most of its 1,370 residents live in Ottawa County’s Harris Township, but the village extends west into Sandusky County as well.

Townships

ZIP Codes

• 43452 — Port Clinton (the county’s most populous ZIP)
• 43449 — Oak Harbor
• 43430 — Genoa
• 43416 — Elmore (also serves the Sandusky County side of the village)
• 43440 — Marblehead (also serves Lakeside)
• 43458 — Rocky Ridge
• 43408 — Clay Center
• 43456 — Put-in-Bay, on South Bass Island (also serves Middle Bass and Isle St. George)

Curtice, Williston, Danbury, Catawba Island, Forest Park, Graytown, Gypsum, Lacarne, Martin, Elliston and Limestone have no ZIP code of their own; mail there is delivered under the nearest incorporated village’s code.

Geography

Ottawa County sits along Lake Erie’s western basin, where two peninsulas — Marblehead and Catawba Island — and a cluster of Bass Islands push out into the lake. Of its 585 square miles, 330 are water, 56 percent of the total, among the highest water shares of any Ohio county. Lake Erie proper covers the county’s north and east, and Sandusky Bay separates the Marblehead Peninsula from the mainland to the south. The Portage River crosses the county’s south-central townships through Elmore and Oak Harbor on its way to the lake, and the Ottawa National Wildlife Refuge and Magee Marsh Wildlife Area, both major bird-migration stopover sites, line the county’s western shore.

Lucas County lies to the northwest, Wood County to the west, Sandusky County to the south, and Erie County to the southeast; Essex County, Ontario, Canada, lies across Lake Erie to the northeast. Lucas County, Wood County, Sandusky County and Erie County all border Ottawa directly.

Demographics

Ottawa County had a population of 40,364 at the 2020 census, and the latest Data USA estimate puts the county at 39,994 residents in 2024 — a rare Ohio county with a shrinking, not growing, population. Oak Harbor and Genoa are its two largest incorporated villages outside Port Clinton itself. Median household income runs $76,101 (2024, Data USA), above Ohio’s statewide figure of $67,769 (2023 ACS). Population density works out to roughly 158 people per square mile of land, low for Ohio, reflecting how much of the county’s total area is lake and bay rather than settled ground.

Economy & Local Life

Manufacturing employs the most workers in the county, about 3,254 people, followed by health care and social assistance at 2,744 and retail trade at 1,731, according to Data USA. The Davis-Besse Nuclear Power Station, in Carroll Township on the Lake Erie shore, is one of the county’s largest single employers and one of Ohio’s two operating nuclear plants. Lakefront tourism drives much of the rest of the local economy: Port Clinton markets itself as the “Walleye Capital of the World” for its Lake Erie fishing, and Put-in-Bay on South Bass Island draws seasonal visitors by ferry from Catawba Island and Port Clinton to its bars, Perry’s Victory and International Peace Memorial, and the surrounding Lake Erie wine country. Marblehead’s limestone quarry, which ships stone by lake freighter, is a long-running industrial employer on the peninsula. Oak Harbor’s biggest annual event is its Apple Festival each October; Port Clinton holds a Walleye Drop on New Year’s Eve.

History

Ohio’s legislature organized Ottawa County on March 6, 1840, carving it from Erie, Lucas and Sandusky counties. The name honors the Odawa (Ottawa) people, or comes from an Odawa word meaning trader — sources differ on which. Port Clinton, founded in 1828 and named for New York governor DeWitt Clinton, became the county seat.

The county’s defining historical event predates its own founding by 27 years. On September 10, 1813, U.S. Navy Commodore Oliver Hazard Perry defeated a British squadron in the Battle of Lake Erie, fought in the waters off South Bass Island, and the victory gave the United States control of Lake Erie for the rest of the War of 1812. Perry’s Victory and International Peace Memorial, a 352-foot column on Put-in-Bay completed in 1915, marks the site and is one of the tallest monuments in the country. Ottawa County voted for the winning presidential candidate in every election from 1964 through 2016, a bellwether streak that ended in 2020.

Getting There

No interstate runs directly through Ottawa County; the Ohio Turnpike, Interstate 80/90, crosses the inland townships to the south. State Route 2 is the main lakeshore road linking Port Clinton to Toledo and Sandusky, and State Route 53 runs north–south through the county to Oak Harbor.

• Toledo — about 34 miles northwest
• Sandusky — about 12 miles southeast
• Cleveland — about 85 miles east

Toledo Express Airport, the region’s nearest commercial airport, sits about 34 miles northwest of Port Clinton. Passenger ferries run seasonally from Port Clinton and Catawba Island to Put-in-Bay, Middle Bass and Kelleys Island; Amtrak does not serve Ottawa County directly, and Toledo is the closest station.

Frequently Asked Questions

Where is Ottawa County located?
It sits on Lake Erie’s western basin in northern Ohio, about 34 miles southeast of Toledo, bordered by Lucas, Wood, Sandusky and Erie counties.

What is the population of Ottawa County?
40,364 at the 2020 census, with a 2024 estimate near 39,994 — one of the few Ohio counties whose population has declined this decade.

How big is Ottawa County?
585 square miles (1,520 km2) total, but only 255 square miles are land; the rest is Lake Erie and Sandusky Bay.

What is the county seat of Ottawa County?
Port Clinton, founded in 1828, is the county seat and the county’s only city.

How many towns and villages are in Ottawa County?
One city (Port Clinton) and seven incorporated villages — Oak Harbor, Genoa, Elmore, Marblehead, Rocky Ridge, Clay Center and Put-in-Bay — plus 14 unincorporated communities and census-designated places.

What ZIP codes does Ottawa County use?
43452 for Port Clinton, 43449 for Oak Harbor, 43430 for Genoa, 43416 for Elmore, 43440 for Marblehead, 43458 for Rocky Ridge, 43408 for Clay Center and 43456 for Put-in-Bay.

What is Ottawa County known for?
The Battle of Lake Erie site off Put-in-Bay, the Marblehead Lighthouse, the Davis-Besse Nuclear Power Station, and Port Clinton’s status as the “Walleye Capital of the World.”

More counties in this state: Towns and villages in Ohio.