Don't Bother to Knock is a 1952 American psychological thriller starring Richard Widmark and Marilyn Monroe and directed by Roy Ward Baker.

The screenplay was written by Daniel Taradash, based on the 1951 novel Mischief by Charlotte Armstrong.

Monroe is featured as a disturbed babysitter watching a child at the same New York hotel where a pilot, played by Widmark, is staying. He starts flirting with her, but over the evening her strange behavior makes him increasingly aware that she is unhinged. How he copes with the situation ends up profoundly impacting all three lives.