Marcia Gay Harden (born August 14, 1958) is an Academy Award- and Saturn Award-winning, as well as a Tony Award- and Emmy Award-nominated American actress.

Harden, one of five children, was born in La Jolla, California, the daughter of Beverly (née Bushfield), a housewife, and Thaddeus Harold Harden, a Texas native who was an officer in the United States Navy. One of her siblings is also named Thaddeus, as is her present spouse. Harden's family frequently moved because of her father's job, living in Japan, Germany, Greece, California and Maryland. She graduated from Surrattsville High School in Clinton, Maryland in 1977, the University of Texas at Austin with a BA in theatre, and the graduate theatre program at New York University's Tisch School of the Arts with a Master of Fine Arts.

In 1992 she played actress Ava Gardner alongside Philip Casnoff as Frank Sinatra in the made for TV miniseries Sinatra. Harden debuted on Broadway in Tony Kushner's Angels in America in 1993, for which she received a Tony Award nomination (Best Featured Actress in a Play) as Harper Pitt (and others). For her film work, she won a Best Supporting Actress Academy Award for playing painter Lee Krasner in Pollock (2000), and was nominated in the same category for Mystic River (2003).