Montgomery Clift is a priest who hears a confession from the parish's caretaker that he's killed a man. Bound by his vow of silence, Clift can't reveal the details of this confession, especially to Karl Malden; inspector assigned to the case.
Malden begins to suspect Clift, after he is seen in mysterious conversations with Anne Baxter at the scene of the crime
The investigation reveals an old romance between the couple and a motive is established, putting Clift on trail for his life.
Hitchcock makes his cameo appearance crossing the top of a staircase during the opening credits.
The 1995 film, "Le Confessionnal," depicts a 1952 flashback scene set in a Quebec church. In the scene, there is a film crew making a movie, which is supposed to be Hitchcock and company working on the film, "I Confess."
Baxter was one of the actresses tested by Hitchcock for the leading role in Rebecca.