Niagara is a 1953 American noir thriller film directed by Henry Hathaway, produced by Charles Brackett, and written by Brackett, Richard L. Breen and Walter Reisch. The film stars Marilyn Monroe, Joseph Cotten, Jean Peters, and Max Showalter (credited as Casey Adams). It was one of 20th Century Fox's biggest box-office hits that year.

Unlike other films noir of the time, which were typically black-and-white, Niagara was filmed in "three-strip" Technicolor (one of the last films to be made at Fox in that format, as a few months later Fox began converting to CinemaScope, which had compatibility problems with three-strip but not with Eastmancolor).

Monroe was given top billing in Niagara, which elevated her to star status. Her next two films, Gentlemen Prefer Blondes (1953) and How to Marry a Millionaire (1953), were even bigger successes.