Books about Mystery and detective stories (sorted alphabetically)
- secret of the old mill Franklin W. Dixon
- Secret of the Sundial Mildred A. Wirt
- Secret Pact Mildred A. Wirt
- Seven Sleuths' Club Carol Norton
- Shadow Passes Roy J. Snell
- Shore Road mystery Franklin W. Dixon
- Signal in the Dark Mildred A. Wirt
- Sign of the Green Arrow Roy J. Snell
- Silver Ring Mystery Helen Wells
- Sisters Grace May North
- S. P. Mystery Harriet Pyne Grove
- Store Boy Jr. Horatio Alger
- Strange Likeness Harriet Pyne Grove
- Swamp Island Mildred A. Wirt
- Tahara Among African Tribes Harold M. Sherman
- Tales of Secret Egypt Sax Rohmer
- Third Warning Roy J. Snell
- Three Eyes Maurice Leblanc
- Ticket to Adventure Roy J. Snell
- Tom the telephone boy; or, The mystery of a message Frank V. Webster
- tower treasure Franklin W. Dixon
- Tracked by Wireless William Le Queux
- Trail of the Green Doll Margaret Sutton
- Uttermost Farthing: A Savant's Vendetta R. Austin Freeman
- Vertical City Fannie Hurst