Books about Detective and mystery stories (sorted alphabetically)
- Monk of Cruta E. Phillips Oppenheim
- Monk of Hambleton Armstrong Livingston
- Monsieur Judas: A Paradox Fergus Hume
- Monsieur Lecoq, v. 1 Emile Gaboriau
- Monsieur Lecoq, v. 2 Emile Gaboriau
- Monsieur Lecoq — Volume 1 (French) Emile Gaboriau
- Monsieur Lecoq — Volume2 (French) Emile Gaboriau
- Moon Rock Arthur J. Rees
- Moons of Mars Dean Evans
- Morganin miljoonat: Salapoliisiromaani (Finnish) Sven Elvestad
- M. or N. "Similia similibus curantur." G. J. Whyte-Melville
- Motor Girls on a Tour Margaret Penrose
- Motor Girls on Crystal Bay; or, The Secret of the Red Oar Margaret Penrose
- Motor Pirate G. Sidney Paternoster
- moving finger Natalie Sumner Lincoln
- Moving Finger E. Phillips Oppenheim
- Mr. Fortune's Practice H. C. Bailey
- Mr. Grex of Monte Carlo E. Phillips Oppenheim
- Mr. Marx's Secret E. Phillips Oppenheim
- Mr. Meeson's Will H. Rider Haggard
- Mrs. Vanderstein's jewels Marion Bryce
- Murder at Bridge Anne Austin
- Murder at Bridge Anne Austin
- Murder at Large Lesley Frost
- Murder in Black Letter Poul Anderson