Cape Fear is a 1962 American psychological thriller film starring Robert Mitchum, Gregory Peck, Martin Balsam, and Polly Bergen. It was adapted by James R. Webb from the novel The Executioners by John D. MacDonald. It was initially storyboarded by Alfred Hitchcock (slated to direct but quit over a dispute), subsequently directed by J. Lee Thompson, and released on April 12, 1962. The movie concerns an attorney whose family is stalked by a criminal he helped to send to jail.

Who starred in the original movie cape fear? Let's have some stream of consciousness first.
To answer the question, consider the following: Cape Fear is a 1962 American psychological thriller film starring Robert Mitchum, Gregory Peck, Martin Balsam, and Polly Bergen. So, the answer is Robert Mitchum.