Mary Lucy Denise Henner (born April 6, 1952), known professionally as Marilu Henner, is an American actress, producer, and New York Times best-selling author best-known for her role as Elaine O'Connor Nardo on the sitcom Taxi from 1978 to 1983 (Seasons 1-5: Entire series).

Born in Chicago, Illinois, to a Greek mother and Polish father, Henner was raised on the northwest side of Chicago in the Logan Square neighborhood. She is the third of six children. Her mother, Loretta, was president of the National Association of Dance and Affiliated Arts and ran the Henner Dance School for 20 years. Henner took her first dance class at age two. Henner started teaching dance at her family’s studio when she was fourteen and choreographed shows at local high schools and colleges until leaving the Chicago area during her third year of college.

While a student at the University of Chicago in the Hyde Park neighborhood 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. Her second role was opposite Richard Gere in the 1978 film Bloodbrothers.