Invisible Inzi of Oz is an Oz book by Virginia and Robert Wauchope, who were fourteen and nine years old, respectively, when they wrote it in 1919, supposedly channeled to them from a Ouija board. It was first serialized in the periodical A Child's Garden from 1925 to 1926, reprinted in the Winter 1980 and Summer 1981 issues of The Baum Bugle, and republished in book form by Buckethead Enterprises of Oz in 1993, with illustrations by Eric Shanower.

Glinda's books of magic have gone missing, so a party consisting of the Wizard, Dorothy Gale, the Scarecrow, and the Patchwork Girl is formed to retrieve them. They discover that they were stolen by the evil magician Kuik Blackbab and are imprisoned, but an invisible creature comes to their aid.