Sylvania is a city in Lucas County, Ohio, United States. The population was 19,011 at the 2020 census. Sylvania is a suburb of Toledo, and encompassed by Sylvania Township. Its northern border is the southern border of the state of Michigan. The name "Sylvania" is borrowed from the Latin sylvan or sylva, meaning "forest land", owing to the dense forests that once made up the region, part of the Great Black Swamp.