The Wishing Horse of Oz (1935) is the twenty-ninth in the series of Oz books created by L. Frank Baum and his successors, and the fifteenth written by Ruth Plumly Thompson. It was Illustrated by John R. Neill. This book marked the point at which Thompson had written more Oz books than Baum himself. This was the last Oz book to feature illustrations in color, and only the first edition has them. A copy of The Wishing Horse of Oz is shown in Martha Coolidge's film, Rambling Rose.