Marilu Lucy Henner (born April 6, 1952) is an American actress, producer and New York Times best-selling author.

Born "Mary Lucy Denise Henner" in Chicago, Illinois, to a Greek mother and Polish father. Marilu's father and brother later changed the family name to Henner for business purposes. Henner was raised on the northwest side of Chicago, Illinois, in the Logan Square neighborhood. Her mother, Loretta, was president of the National Association of Dance and Affiliated Arts and ran the Henner Dance School ("disguised as a three-car garage") for 20 years. Henner took her first dance class at age 2.

While a student at the prestigious University of Chicago, in the Hyde Park district of Chicago, Henner originated the role of "Marty" in the pre-Broadway Kingston Mines' production of Grease, in 1971. When the show was discovered and moved to Broadway, she was asked to reprise the role; however, she chose instead to play "Marty" in the national touring company alongside John Travolta, who played, "Doody." Additional Broadway credits for Henner include, Over Here!, with Travolta, revivals of Pal Joey, Chicago, Social Security and The Tale of the Allergist's Wife. Her first film appearance was in the 1977 sleeper-hit, "Between The Lines," co-starring then-unknowns Jeff Goldblum, Lindsay Crouse, John Heard and Jill Eikenberry.