Who's Who in Oz is a guidebook to the characters in the classic Oz novels. It was written by Jack Snow, and published by Reilly & Lee in 1954. A reprint of the original edition was issued by Peter Bedrick Books in 1988.
Snow's guide includes characters from all of the "Famous Forty" books except the last, Eloise Jarvis McGraw's Merry Go Round in Oz (1963), which had not yet been published when Snow wrote. His Who's Who contains capsule biographies of 630 Oz characters:
- 221 from the 14 works of L. Frank Baum
- 329 from the 19 works of Ruth Plumly Thompson
- 38 from the 3 works of John R. Neill
- 25 from the 2 works by Snow himself
- 17 from 1 work by Rachel Cosgrove.
The volume concludes with short summaries of the 39 books, and brief biographical notices of the eight pre-1954 Oz authors and illustrators.
The book also features more than 490 illustrations from the Oz canon by Neill, Frank Kramer, and Dirk Gringhuis. (None of W. W. Denslow's pictures from The Wonderful Wizard of Oz is included; that was the one Oz book not published by the Reilly & Britton/Reilly & Lee firm.)
Who's Who in Oz includes one noteworthy anomaly: Snow treated the Soldier with the Green Whiskers and the Guardian of the Gates as one character, though other commentators, authorities, and fans recognize them as two separate figures. Snow listed the Soldier under both his names — as Omby Amby (the name Baum gave to him in Ozma of Oz) and as Wantowin (Thompson re-christened him Wantowin Battles in Ozoplaning with the Wizard of Oz).