Special Collections that can be found at Tiffin-Seneca Public Library include:

- Tiffin Postcard Collection

- Junior Home and Flat Rock Orphanages

- Tiffin Centennial Books

- History of the Tiffin Fire Department

- Bicentennial Sketches-Myron Barnes

- Life and speeches of William H. Gibson

- Vertical File- includes pamphlets, articles

- First Families of Seneca County applications

- File with folders of those in First Families

- File with information on other Seneca County families

- Printed family books donated by families of Seneca County

- “Seneca County Shelf”-a variety of reference books for Seneca County

- Ohio Collection- general works

- County Home Infirmary Records 1881-1966  and  Naturalization records 1852-1902

- Sisters of the Third Order of St. Francis of Penance and Charity 1869-1942

- Not with Silver or Gold by Sisters of the Precious Blood

Information on Tiffin Industries
American Standard, National Machinery, Diehl Wagon Works, Tiffin Glass, Belgian glass, Webster, and other Tiffin industries.