Justin G. Schiller was one of the principal founders of The International Wizard of Oz Club in 1957.
On 3 November 1956, the precocious Schiller served as one of the hosts of the original television broadcast of the 1939 MGM film of The Wizard of Oz, along with Bert Lahr and the ten-year-old Liza Minelli. In January 1957, Schiller, then thirteen years old, sent out the original solicitation letter for members for a new fan club devoted to Oz. He served as the new club's first secretary, succeeded by Fred M. Meyer in 1961.
Schiller is a book collector by avocation and a rare book dealer by trade; he specializes in children's books and art books, his business headquartered in New York City. Schiller is the author of a number of journal and magazine articles, and the books
- Realms of Childhood (1983)
- Nonsensus (1988)
- Digging for Treasure: An Adventure in Appraising Rare and Collectible Children's Books (1998)
- Pioneering Collectible Children's Books (2002)
- Sendak All Around (2003).
He has also compiled the catalogues of museum exhibitions of children's literature books and art. His article "Fifty Years of the Oz Club" appeared in the 50th anniversary issue of The Baum Bugle, Autumn 2007.
The Bibliographical Society of America offers a Justin G. Schiller Prize for Bibliographical Work in Pre-20th-Century Children's Books.