All the King's Men is a 1949 American political drama film written, produced, and directed by Robert Rossen. It is based on Robert Penn Warren's Pulitzer Prize-winning 1946 novel of the same name. It stars Broderick Crawford, John Ireland, Mercedes McCambridge, and Joanne Dru. The film centers on the rise and fall of an idealistic-but-ruthless politician in the American South, patterned after Louisiana Governor Huey Long.

Released by Columbia Pictures on November 8, 1949, the film received widespread acclaim from critics, and was a commercial success. At the 22nd Academy Awards the film was nominated for seven Oscars and won three; Best Picture, Best Actor for Crawford, and Best Supporting Actress for McCambridge, making an impressive film debut. The film also won five Golden Globes, and was nominated for the Golden Lion at the Venice Film Festival.

In 2001, All the King's Men was deemed "culturally, historically, or aesthetically significant" by the Library of Congress and was selected for preservation in the United States National Film Registry.