Henry Fonda, still struggling to became a big Hollywood star, tried to avoid being a contract player for 20th Century-Fox because he wanted the ability to independently choose his own projects (an increasing number of stars at the time were trying to gain such independence). But when the much-coveted part of Tom Joad was offered to him, Fonda hesitantly gave in and signed a contract to work with the studio for seven years because he knew it would be the role of a lifetime.
Darryl F. Zanuck was heavily involved in all aspects of the production, as he saw it as a personal project. In fact, so meticulous and carefully thought-through was his editing of Nunnally Johnson's screenplay that Johnson himself praised Zanuck for his attention to detail.
Real-Life Relative: Dorris Bowdon (Rosasharn) was married to screenwriter Nunnally Johnson.
Stillborn Franchise: A sequel was in the works at Fox the year after the film's release. It was tentatively named after the first film's fake working title, Highway 66.
Samuel Goldwyn's story editor persuaded him to buy the book with Gary Cooper starring as Tom Joad. Goldwyn disliked the book and suggested that "Zanuck make a mess of it". Whoops.
James Stewart was originally set to play Al, with Walter Brennan as Pa Joad.
Working Title: The production had a fake working title, Highway 66, so that the shoot of the controversial novel would not be affected by union problems. Much of the dire straits portrayed in the film continued during and after the release of the movie.