Galaxy novels, sometimes titled Galaxy Science Fiction Novels, were a series of mostly reprint science fiction novels between 1950 and 1961.  The series was started in 1950 by H.L. Gold as a companion publication to Galaxy Science Fiction magazine. Each issue consisted of one (often abridged) novel published in the digest size format, giving the books in the series the appearance of digest magazines.

In 1959 the series was sold to Beacon Books, which changed the format to small size paperback and introduced its own numbering scheme indicated by the bracketed number following the entries below. The contents of some books was revised to add mild sexual content and the titles altered accordingly.*

1950
1. Eric Frank Russell, Sinister Barrier (1943)
2. Jack Williamson, The Legion of Space (1947)

1951
3. Arthur C. Clarke, Prelude to Space (1951)
4. S. Fowler Wright, The Amphibians (1925)
5. S. Fowler Wright, The World Below (1949)
6. Raymond F. Jones, The Alien (1951)
7. Clifford D. Simak, Empire (1951)

1952
8. Olaf Stapledon, Odd John (1936)
9. William F. Temple, Four Sided Triangle (1949)
10. Jay Franklin, Rat Race (1950)
11. Wilson Tucker, The City in the Sea (1951)
12. Sam Merwin, Jr., The House of Many Worlds (1951)

1953
13. John Taine, Seeds of Life (1953)
14. Isaac Asimov, Pebble in the Sky (1950)
15. Leslie Mitchell, Three Go Back (1932)
16. James Blish, The Warriors of Day (1953)
17. Lewis Padgett, Well of the Worlds (Startling Stories, March 1952)
18. Edmond Hamilton, City at World's End (1951)
19. James Blish, Jack of Eagles (1952)

1954
20. Murray Leinster, The Black Galaxy (1949)
21. Jack Williamson, The Humanoids (1949, expanded version of  "With Folded Hands...", Astounding Science Fiction July 1947)
22. Sam Merwin, Jr., Killer To Come (1953)
23. David Reed, Murder in Space

1955
24. L. Sprague de Camp, Lest Darkness Fall (1939)
25. Murray Leinster, The Last Spaceship

1956
26. Lewis Padgett, Chessboard Planet
27. Malcolm Jameson, Tarnished Utopia (Startling Stories, March 1942)

1957
28. Fritz Leiber, Destiny Times Three
29. Ron Hubbard, Fear
30. Fletcher Pratt, Double Jeopardy
31. C.L. Moore, Shambleau
32. F.L. Wallace, Address: Centauri

1958
33. Hal Clement, Mission of Gravity
34. Manly Wade Wellman, Twice in Time
35. Frank Riley and Mark Clifton, The Forever Machine

1959
36. Olaf Stapledon, Odd John (1936, 2nd printing as a Galaxy Novel) [236]
37. Raymond F. Jones, The Deviates [242]
38. George O. Smith, Troubled Star [256]
39. Laurence Janifer (as "Larry M. Harris") and Randall Garrett, Pagan Passions [263]

1960
40. Poul Anderson, Virgin Planet [270]
41. Philip José Farmer, Flesh (1960) [277]
42. Sam Merwin, Jr., The Sex War (1960, expanded version of "The White Widows", Startling Stories, October 1953) [284]
43. Philip José Farmer, A Woman A Day (1960, expanded version of "Moth and Rust",  Startling Stories, June) [291]
44. A.E. Van Vogt, The Mating Cry (1960, revision of The House That Stood Still, 1950) [298]

1961
45. Brian Aldiss, The Male Response (1961) [305]
46. Cyril Judd, Sin in Space (1952, originally as Outpost Mars) [312]

*some text and information based on Wikipedia entries.