Sandusky County is a county located in the northwestern part of the U.S. state of Ohio. It is southeast of the Toledo Metropolitan Area. As of the 2010 census, the population was 60,944. Its county seat is Fremont. The county was formed on February 12, 1820, from portions of Huron County. The name is derived from the Wyandot word meaning "water" (""). The Sandusky River runs diagonally northeast through the county to its mouth on Sandusky Bay. The bay opens into Lake Erie.