Nancy Anne Allen (born June 24, 1950) is an American actress. She came to prominence for her performances in several films directed by Brian De Palma in the 1970s and early 1980s. Her accolades include a Golden Globe Award nomination and three Saturn Award nominations.

The daughter of a New York City police lieutenant, Allen was raised in the Bronx, and attended the High School of Performing Arts, aspiring to have a career as a dancer. In her early twenties, she shifted her focus to acting and relocated to Los Angeles to pursue a career there. Her first major role was as Chris Hargensen in Brian De Palma's film adaptation of Carrie (1976). Allen was subsequently cast as the lead in the Robert Zemeckis-directed comedy I Wanna Hold Your Hand (1978), followed by a supporting part in Steven Spielberg's 1941 (1979).