Tracy first discovered his talent for acting while attending Ripon College, and he later received a scholarship for the American Academy of Dramatic Arts. He spent seven years in the theatre, working in a succession of stock companies and intermittently on Broadway. Tracy's breakthrough came in 1930, when his lead performance in The Last Mile caught the attention of Hollywood. After a successful film debut in John Ford's Up the River starring Tracy (and also featuring Humphrey Bogart), he was signed to a contract with Fox Film Corporation. His five years with Fox featured one acting tour de force after another that were usually ignored at the box office, and he remained largely unknown to audiences after 25 films, almost all of them starring Tracy as the leading man. None of them were hits although his performance in The Power and the Glory (1933) was praised at the time.

In 1935, Tracy joined Metro-Goldwyn-Mayer, then Hollywood's most prestigious studio. His career flourished from Fury (1936) onwards, and in 1937 and 1938 he won consecutive Oscars for Captains Courageous and Boys Town. He made three box-office successes supporting Clark Gable, the studio's most prominent leading man so that by the early 1940s, Tracy was one of the studio's top stars. In 1942, he appeared with Katharine Hepburn in Woman of the Year, beginning another partnership leading to nine movies over 25 years.