Kelleys Island is both a village in Erie County, Ohio, United States, and the island which it fully occupies in Lake Erie. The British originally called it Sandusky Island. Later the United States took it over and officially designated it as Island Number 6 and Cunningham Island. It was renamed as Kelleys Island in 1840 by brothers Datus and Irad Kelley, who had purchased nearly the entire island.
Kelleys Island was previously occupied by Native Americans of the area. During the beginning of the War of 1812, the island was used as a military rendezvous post, first by the British and later by the US Military. During the early 19th century, the island was mostly uninhabited. After the Kelley brothers purchased the land, there was commercial development through extraction of the island's limestone and lumber resources, and the population began to grow with workers and families. There was also growing of grapes as a commodity crop. As of the 2010 census, the island's population was 312.
Today, Kelleys Island is primarily a vacation destination, and is visited by thousands of people each summer. Notable attractions include its various beaches, parks, and campgrounds. Several ferries provide regular transport to the mainland for most travelers; the island also features a number of marinas, as well as a small airfield for private planes. It is the largest of the American Lake Erie Islands, and is a part of the Sandusky, Ohio Metropolitan Statistical Area.