Books about Detective and mystery stories (sorted alphabetically)
- Jerry Todd and the Talking Frog Leo Edwards
- Jimmy Drury: Candid Camera Detective David O'Hara
- Joe Leslie's Wife; or, a Skeleton in the Closet M.D. Alexander Robertson
- Josie O'Gorman Emma Speed Sampson
- Josie O'Gorman and the Meddlesome Major Emma Speed Sampson
- Juggernaut Alice Campbell
- Kadonnut mies (Finnish) J. S. Fletcher
- Kauhun laakso 1: Murhenäytelmä Birlstonen kartanossa (Finnish) Arthur Conan Doyle
- Kauhun laakso 2: Salaseuralaiset (Finnish) Arthur Conan Doyle
- Keeban Edwin Balmer
- Kellanpunainen timantti (Finnish) J. S. Fletcher
- King of Diamonds: A Tale of Mystery and Adventure Louis Tracy
- Knock three-one-two Fredric Brown
- Kostajan kourissa: Salapoliisikertomus (Finnish) Sven Elvestad
- Kuparilipas (Finnish) J. S. Fletcher
- La Chance Mine Mystery Susan Morrow Jones
- Lady from Nowhere: A Detective Story Fergus Hume
- Lady Jim of Curzon Street: A Novel Fergus Hume
- Lady Molly of Scotland Yard Baroness Emmuska Orczy Orczy
- Lake Mystery Marvin Dana
- Lanagan, Amateur Detective Edward H. Hurlbut
- Last Stroke: A Detective Story Lawrence L. Lynch
- Launch Boys' Adventures in Northern Waters Edward Sylvester Ellis
- Layton Court mystery Anthony Berkeley
- Leak Jacques Futrelle