The Keys of the Kingdom is a 1944 American film based on the 1941 novel The Keys of the Kingdom by A. J. Cronin. The film was adapted by Nunnally Johnson, directed by John M. Stahl, and produced by Joseph L. Mankiewicz. It stars Gregory Peck, Thomas Mitchell, and Vincent Price, and tells the story of the trials and tribulations of a Catholic priest who goes to China to evangelize.