Marsha Virginia Hunt attended the Theodore Irving School of Dramatics during her high school years. She was a singer and a model before Paramount Pictures signed her to a contract in 1934. At 18 years of age, she made her film debut in The Virginia Judge.
During the late 1930s and into the 1940s, Hunt signed a number of petitions promoting liberal ideals. She was also a member of the Committee for the First Amendment. Because of this association, her name appeared in the pamphlet Red Channels. Although she and her husband, Robert Presnell, were never called before the House Un-American Activities Commission (HUAC), like Charlie Chaplin, their names were put on the blacklist, and they found it extremely difficult to find work. On October 27, 1947, she flew with a group of about 30 actors, directors, writers, and filmmakers (including John Huston, Humphrey Bogart, Lauren Bacall and Danny Kaye), to Washington D.C. to protest the actions of Congress. When she returned to Hollywood three days later, things had changed. She was asked to denounce her activities if she wanted to find more work—but she refused. She did keep working until the publication of Red Channels, but afterwards it became very hard.
She had worked steadily from 1935 until 1949, appearing in 52 films. In 1944 she polled seventh in a list by exhibitors of "Stars of Tomorrow". After being blacklisted, she appeared in only three films in the next eight years. In 1957, she started getting more work, appearing in six films during the next three years, at which time she semi-retired in 1960. Since then she has appeared only in small roles in five films and numerous television shows, including an episode of the ABC medical drama Breaking Point.
In 1971, she would appear in a movie written by fellow blacklist member, Dalton Trumbo (whom Kirk Douglas had gotten back on the screen with Spartacus), in the movie Johnny Got His Gun, playing the mother of Timothy Bottoms.
Since 1980, she has been the honorary mayor of Sherman Oaks, California. Hunt is still very liberal, and is very concerned with such issues as global pollution, worldwide poverty, peace in third world nations, and population growth.
On February 8, 1988, she appeared in Star Trek: The Next Generation, in the episode "Too Short a Season" as Anne Jameson, wife of an admiral who took an age reversing drug.
In 1993, her book The Way We Wore: Styles of the 1930s and '40s and Our World Since Then was published by Fallbrook Publishing.
Hunt played Elizabeth Lyons in a 2005 movie, Chloe's Prayer. She produced the CD Tony London: Songs From The Heart with the Page Cavanaugh Trio that includes two of the fifty songs that Hunt has composed.
As of 2007, Marsha Hunt has served for many years and continues to serve on the Advisory Board of Directors for the San Fernando Valley Community Mental Health Center, a large non-profit in the San Fernando Valley where she continues to advocate for adults and children affected by homelessness and mental illness.
In January 2008, Hunt appeared in a short film noir, The Grand Inquisitor, as Hazel Reedy, the could-be widow of one of America's most famous unapprehended serial killers. The film premiered at the 6th annual Noir City Film Festival in San Francisco.
In 1938, she married film director Jerry Hopper; they were divorced in 1943. Three years later, in 1946, she married television and film writer Robert Presnell, Jr., which lasted until his death in June 1986.