National Historic Register properties in Seneca county/parish, Ohio

• Omar Chapel (Attica)
• Heter Farm (Bellevue)
• Henny Barn (Flat Rock)
• Cory, Ambrose, House (Fostoria)
• Fostoria Downtown Historic District (Fostoria)
• Michaels Farm (Kansas)
• Camp Pittenger Historic District (McCutchenville)
• St. Boniface Roman Catholic Church, School, Rectory, and Convent of the Sister of the Precious Blood (New Riegel)
• Aigler Alumni Building (Tiffin)
• Bagby-Hossler House (Tiffin)
• Beatty Glass Company (Tiffin)
• Black Student Union Center (Tiffin)
• Bowman's Distillery (Tiffin)
• College Hall (Tiffin)
• Downtown Tiffin Historic District (Tiffin)
• Fine Arts Building (Tiffin)
• Fort Ball-Railroad Historic Disrict (Tiffin)
• Founders Hall, Heidelberg College (Tiffin)
• France Hall (Tiffin)
• Gerhart-Rust Residence (Tiffin)
• Great Hall (Tiffin)
• Hanson Machinery Company (Tiffin)
• Hedges-Hunter-Keller-Bacon Gristmill (Tiffin)
• Hunter, William, House (Tiffin)
• Laird Hall (Tiffin)
• Miami Street Grade School (Tiffin)
• Mueller Brewery (Tiffin)
• Mueller, Christ, House (Tiffin)
• National Home, Daughters of America (Tiffin)
• National Orphans' Home, Junior Order United American Mechanics (Tiffin)
• Northeast Tiffin Historic District (Tiffin)
• North Sandusky Street Historic District (Tiffin)
• Octagon, The (Tiffin)
• Ohio Lantern Company (Tiffin)
• Pfleiderer Center for Religion and the Humanities (Tiffin)
• Pleasant Ridge United Methodist Church and Cemetery (Tiffin)
• President's House (Tiffin)
• Social Science House (Tiffin)
• Springdale (Tiffin)
• Tiffin Agricultural Works (Tiffin)
• Tiffin Art Metal Company (Tiffin)
• Tiffin Waterworks (Tiffin)
• Umsted Farm (Tiffin)
• Wagner Brothers Bottling Works (Tiffin)
• Webster Manufacturing (Tiffin)
• Williard Hall (Tiffin)