Books in Science Fiction (sorted alphabetically)
- Masters of Space E. Everett Evans and E. E. Smith
- Mate in Two Moves Winston K. Marks
- Mathematicians Arthur Feldman
- Mating of the Moons Bryce Walton
- Matter of Importance Murray Leinster
- Matter of Magnitude Al Sevcik
- Matter of Proportion Anne Walker
- Matter of Protocol Jack Sharkey
- McIlvaine's Star August Derleth
- Measure for a Loner Jim Harmon
- Measure of a Man Randall Garrett
- Medal of Honor Mack Reynolds
- Med Ship Man Murray Leinster
- Meeting of the Board Alan Edward Nourse
- Meeting of the Minds Robert Sheckley
- Memory of Mars Raymond F. Jones
- Men in the Walls William Tenn
- Mercenaries H. Beam Piper
- Mercenary Mack Reynolds
- Metal Monster Abraham Merritt
- Metal Moon Roman Frederick Starzl and Everett C. Smith
- Metamorphosis Charles V. De Vet
- Mex Laurence M. Janifer
- Micro-Man Forrest J. Ackerman
- Mid Pleasures and Palaces James McKimmey