Jefferson is a village in Ashtabula County, Ohio, United States. The population was 3,120 at the 2010 census. It is the county seat of Ashtabula County. Modern-day Jefferson sports the world's only perambulator museum and a historical complex including several restored 19th-century buildings. Joshua Giddings' law office has also been restored as a museum. Annual village events include the Ashtabula County Fair, the Strawberry Festival, Jefferson Days, and the Covered Bridge Festival.