Books about Detective and mystery stories (sorted alphabetically)
- Poppy Ott and the galloping snail Leo Edwards
- Postmaster's Daughter Louis Tracy
- Power-House John Buchan
- Prince of Swindlers Guy Boothby
- Prinssi ja kaunis näyttelijätär: Salapoliisikertomus (Finnish) Sven Elvestad
- Prisoners in Devil's Bog: A Skippy Dare Mystery Story Percy Keese Fitzhugh
- problem of Cell 13 Jacques Futrelle
- Profiteers E. Phillips Oppenheim
- Punainen leski: Romaani (Finnish) Sven Elvestad
- Purple Fern Fergus Hume
- Queen of Hearts Wilkie Collins
- Quest of the Sacred Slipper Sax Rohmer
- Quintus Oakes: A Detective Story Charles Ross Jackson
- Rabok (Hungarian) Ferenc Molnár
- Radio Boys Loyalty; Or, Bill Brown Listens In Wayne Whipple and S. F. Aaron
- Radio Detectives A. Hyatt Verrill
- Radio Detectives in the Jungle A. Hyatt Verrill
- Radio Detectives Under the Sea A. Hyatt Verrill
- radio girls of Roselawn : or, A strange message from the air Margaret Penrose
- Rainbow Feather Fergus Hume
- Ramshackle House Hulbert Footner
- rasp Philip MacDonald
- Raspberry Jam Carolyn Wells
- Ravensdene Court J. S. Fletcher
- Rayner-Slade Amalgamation J. S. Fletcher