Seneca County Ohio (Historic Districts) has 7 places on the National Register of Historic Places including 3 places of Statewide significance. Significant places include Camp Pittenger Historic District, Downtown Tiffin Historic District and National Orphans' Home, Junior Order United American Mechanics, Camp Pittenger Historic District and Fort Ball-Railroad Historic Disrict.
The famous person Luther Hall is associated with one of more of the Seneca County historic places. Prominent architectural styles found in Seneca Country are Italianate, Bungalow/Craftsman and Greek Revival.