Marblehead is a village in Ottawa County, Ohio, United States. The population was 865 at the 2020 census. It sits at the tip of the Marblehead Peninsula, which divides Lake Erie proper from Sandusky Bay. Marblehead is part of the area that is referred to regionally as Vacationland due to the large number of tourists who flock to the area in the summer months. It remains a popular vacation destination due to its lake frontage, ferry service to the Lake Erie Islands, quality sport fishery, the nearby Lakeside Chautauqua, and the Cedar Point amusement park. Marblehead is also home to the Lakeside Daisy State Nature Preserve, home to the only natural U.S. population of the Lakeside Daisy, an endangered species.

Ottawa County is a county located in the northwestern part of the U.S. state of Ohio. As of the 2020 census, the population was 40,364. Its county seat is Port Clinton. The county is named either for the Ottawa (Odawa) Indigenous peoples who lived there, or for an Indigenous word meaning "trader".