Karen Jane Allen (born October 5, 1951) is an American actress, best known for her role as Marion Ravenwood in Raiders of the Lost Ark (1981). Allen has also had roles in the films National Lampoon's Animal House (1978), The Wanderers (1979), Split Image (1982), Starman (1984), Scrooged (1988), The Sandlot (1993), Poster Boy (2004), and Indiana Jones and the Kingdom of the Crystal Skull (2008), where she reprised her role as Marion Ravenwood.

Allen was born in Carrollton, rural western Illinois, the daughter of Patricia A. (née Howell), a teacher, and Carroll Thompson Allen, an FBI agent. Allen spent her first 10 years traveling around the country with her parents and two sisters. After graduating from DuVal Senior High School, in Glenn Dale, Maryland at 17, she moved to New York City to study art and design at Fashion Institute of Technology. She later attended the University of Maryland, College Park and spent time traveling through South and Central America. In 1974, Allen joined a theater group and three years later moved back to New York City and studied at the Lee Strasberg Theater Institute.

In 1978, Allen made her major film debut in National Lampoon's Animal House. Her next two film appearances were in The Wanderers in 1979 and A Small Circle of Friends in 1980, where she played one of three radical college students during the 1960s. She also appeared (as a guest star) in the 1979 pilot episode of the long-running CBS series Knots Landing.