Nancy Allen (born June 24, 1950 in New York City, New York) is an American film actress and a native of New York. Her best-known films are Blow Out, Dressed to Kill and the RoboCop cycle.

Brian De Palma, second of Allen's three husbands, directed her in Blow Out (1981); Dressed to Kill (1980); Home Movies (1979); and in Carrie (1976), where she portrayed antagonistic teenager Chris Hargensen.

Other credits include a small role opposite Jack Nicholson in The Last Detail (1973), and Robert Zemeckis’ first feature film I Wanna Hold Your Hand (1978).

After her divorce from De Palma, her film career went into a noticeable decline. Some have suggested/joked that her divorce from De Palma divorced her from good films, though she did go on to co-star in 1987's Robocop, where she played the title character's durable female partner Anne Lewis. In more recent years, she had a small but notable role in 1998's Out of Sight, directed by Steven Soderbergh.