Fremont is a city in and the county seat of Sandusky County, Ohio, United States. The population was 17,375 at the 2000 census. Fremont is located at 41°20′56″N 83°7′2″W / 41.34889°N 83.11722°W / 41.34889; -83.11722 (41.348909, -83.117123), along the Sandusky River.