The Iron Major is a 1943 American biographical film about the famed college football coach and World War I hero, Frank Cavanaugh. Directed by Ray Enright, the screenplay was written by Aben Kandel and Warren Duff, based on Florence E. Cavanaugh's story. Produced and directed by RKO Radio Pictures, the film premiered in Boston on October 25, 1943. The picture stars Pat O'Brien as Major Cavanaugh, along with Ruth Warrick and Robert Ryan.