LeRoy started out as an actor in silent movies; he made a successful transition to directing in the late 1920s, and then to producing in the 1930s. He became a producer with MGM, in a contract with the studio that took effect on 3 February 1938. (He earned $6000 per week, double the salary of any other MGM producer.) The Wizard of Oz was the first movie he produced for the studio. Reports conflict on the respective roles of LeRoy and assistant producer Arthur Freed in the creation of the film.
Reportedly, LeRoy also directed some scenes of the film, making him one of the round robin of directors who worked on the movie.