List of official 40 OZ titles

1. The Wizard of Oz (originally published as The Wonderful Wizard of Oz) (L. Frank Baum, 1900)

2. The Land of Oz (originally published as The Marvelous Land of Oz) (L. Frank Baum, 1904) Slideshow
3. Ozma of Oz (L. Frank Baum, 1907) Slideshow
4. Dorothy and the Wizard in Oz (L. Frank Baum, 1908) Slideshow
5. The Road to Oz (L. Frank Baum, 1909) Slideshow
6. The Emerald City of Oz (L. Frank Baum, 1910) Slideshow
7. The Patchwork Girl of Oz (L. Frank Baum, 1913) Slideshow
8. Tik-Tok of Oz (L. Frank Baum, 1914) Slideshow
9. The Scarecrow of Oz (L. Frank Baum, 1915) Slideshow
10. Rinkitink in Oz (L. Frank Baum, 1916) Slideshow
11. The Lost Princess of Oz (L. Frank Baum, 1917) Slideshow
12. The Tin Woodman of Oz (L. Frank Baum, 1918) Slideshow
13. The Magic of Oz (L. Frank Baum, 1919) Slideshow
14. Glinda of Oz (L. Frank Baum, 1920) Slideshow
15. The Royal Book of Oz (Ruth Plumly Thompson [but originally attributed to L. Frank Baum], 1921) Slideshow
16. Kabumpo in Oz (Ruth Plumly Thompson, 1922) Slideshow
17. The Cowardly Lion of Oz (Ruth Plumly Thompson, 1923) Slideshow
18. Grampa in Oz (Ruth Plumly Thompson, 1924) Slideshow
19. The Lost King of Oz (Ruth Plumly Thompson, 1925) Slideshow
20. The Hungry Tiger of Oz (Ruth Plumly Thompson, 1926) Slideshow
21. The Gnome King of Oz (Ruth Plumly Thompson, 1927) Slideshow
22. The Giant Horse of Oz (Ruth Plumly Thompson, 1928) Slideshow
23. Jack Pumpkinhead of Oz (Ruth Plumly Thompson, 1929) Slideshow
24. The Yellow Knight of Oz (Ruth Plumly Thompson, 1930) Slideshow
25. Pirates in Oz (Ruth Plumly Thompson, 1931) Slideshow
26. The Purple Prince of Oz (Ruth Plumly Thompson, 1932) Slideshow
27. Ojo in Oz (Ruth Plumly Thompson, 1933) Slideshow
28. Speedy in Oz (Ruth Plumly Thompson, 1934) Slideshow
29. The Wishing Horse of Oz (Ruth Plumly Thompson, 1935) Slideshow
30. Captain Salt in Oz (Ruth Plumly Thompson, 1936)
31. Handy Mandy in Oz (Ruth Plumly Thompson, 1937)
32. The Silver Princess in Oz (Ruth Plumly Thompson, 1938)
33. Ozoplaning with the Wizard of Oz (Ruth Plumly Thompson, 1939)
34. The Wonder City of Oz (John R. Neill, 1940)
35. The Scalawagons of Oz (John R. Neill, 1941)
36. Lucky Bucky in Oz (John R. Neill, 1942)
37. The Magical Mimics in Oz (Jack Snow, 1946)
38. The Shaggy Man of Oz (Jack Snow, 1949)
39. The Hidden Valley of Oz (Rachel R. Cosgrove, 1951
40. Merry Go Round in Oz (Eloise Jarvis McGraw and Lauren McGraw Wagner, 1963)