Fremont is a city in and the county seat of Sandusky County, Ohio, United States. The population was 16,734 at the 2010 census. It was the home of Rutherford B. Hayes, who served as President of the United States from 1877 to 1881. The Rutherford B. Hayes Presidential Center remains one of the focal points of Fremont, OH. The National Arbor Day Foundation designated Fremont as a Tree City USA.