Ottawa County was formed March 6, 1840. There was a 60-year fight between Port Clinton and Oak Harbor as to where the Court House should be located The matter was brought before the State Legislature five times. Each time Port Clinton was selected as the location.

Ottawa is an Indian word meaning "trader." The Ottawa tribe traded furs and skins with early white settlers.

Ottawa County is located on Lake Erie about 15 miles southeast of Toledo, Ohio. It is situated in the Black Swamp district. The county has a level surface and includes the Portage River. The peninsula extending into the lake has abundant limestone deposits.

Port Clinton is the only city in the county and is the county seat. The Ottawa County Courthouse has been placed on the National Register of Historic Places.

The outside of the Court House is Amherst Ohio sandstone. Each side of the front entranceway has a carving of an Ottawa Indian. The tall bell tower sounds the time of the clock that is visible from all sides of the building.

The inside features mosaic floors, marble wainscoting, and a pink marble staircase. The Court House is adorned with murals. One is of Perry's victory during the War of 1812. This may be seen from the first and second floors. The others are in the dome, four of which represent means of making a living in the county in 1900.

Names of men in the county who fought in early wars are engraved in marble on the north wall of the assembly room and in the main hallway. The cornerstone gives the date of 1899; the courthouse was actually completed May 20, 1901 and is in the final stage of complete renovation and restoration.

The county's peninsula and the islands to the north were part of the Connecticut Western Reserve.

During the War of 1812 the fleet of Commodore Oliver H. Perry put in near South Bass Island before defeating the British in the Battle of Lake Erie. The site is now called Put-in-Bay. Perry's ship "Niagara" flew a banner with the words "Don't give up the ship." Afterwards, Perry reported to General Harrison the well-known words, "We have met the enemy and they are ours..." The Peace Monument at Put-in-Bay entombs both the American and British officers killed in the battle.

Middle and North Bass Islands were settled by Germans who found the lands suitable for growing grapes and making wine. Middle Bass Island was once a retreat for President Hayes, Cleveland, Harrison and Taft. In 1854 a Spanish merchant bought five islands, including Put-in-Bay which was first a sheep ranch and later a fruit farm. Before World War I, a famous resort here, the Victory Hotel, was supposed to be the largest in the country, with the first swimming pool allowing ladies and gentlemen to swim together. The resort was destroyed by fire in 1919. The island is now a popular summer vacation area. The islands and the peninsula have been used for various public functions, such as camp meetings and soldiers' reunions.

Built in 1820, the oldest lighthouse in Ohio stands at the top of Marblehead peninsula which has been the roughest point on Lake Erie since the beginning of navigation on the Great Lakes.

Ottawa County is made up by various communities that include seven (7) villages, twelve (12) townships and the only city in Ottawa County, Port Clinton.