Marion Mack was born Joey Marion McCreery in Mammoth, Utah. After graduating from high school, she sent a letter and a photograph to director Mack Sennett expressing her desire to be an actress. Sennett’s manager wrote back informing Mack that they would give her an interview if she ever came to Hollywood. Mack, her father and her stepmother traveled to Hollywood shortly thereafter and sneaked into Sennett’s Keystone Studios. Much to her father’s disapproval, Mack was hired by Sennett as a “bathing beauty” for $25 a week. Her film debut was in On a Summer Day (1921). After appearing in several short films for Sennett, she left Keystone and signed with Mermaid Pictures for $100 a week. While at Mermaid, she appeared in various comedy shorts and worked at Universal where she had roles in several Westerns. Mack returned to Mermaid after a year. In 1923, she co-wrote and appeared in a semi-autobiographical film, Mary of the Movies. Around the time, she adopted the stage name “Marion Mack”. Mary of the Movies was a box office success and Mack went on to leading roles in the action/crime-drama One of the Bravest (1925) and the drama Carnival Girl (1926). In 1926 she was cast in her best known role as Annabelle Lee, the estranged girlfriend of Buster Keaton’s character, Johnnie Gray, in the American Civil War comedy film The General. The film was a moderate success but failed to make a profit because the budget was high. Mack appeared in her final film Alice in Movieland, in 1928.

Marion Mack gave up acting after appearing in Alice in Movieland because she found the strain of filming for such long periods to be too taxing (The General was shot over a six-month period in Oregon). After her retirement from acting, she began a career as a screenwriter and penned scripts for short films for Metro-Goldwyn-Mayer and Warner Bros. Mack’s husband, producer Louis Lewyn, produced the films. One of the films she scripted was for Keaton, the 1938 short Streamlined Swing. By the 1940s, short films began to fall out of favor and Mack’s husband’s health was declining. In 1949, she took up yet another career as a real estate broker in Orange County, California. Mack and her husband settled in Costa Mesa, California. The couple also owned an estate in Beverly Hills and continued to socialize with people whom they met when they worked in the film industry, including Rudy Vallee and Clara Bow.

In 1970, film historian Raymond Rohauer tracked Mack down at her Costa Mesa home due to renewed interest in The General. While the film was not a commercial or critical success when it was first released, it later found an audience and has since become cited as one of Buster Keaton’s greatest films. To support the film, Mack attended screenings of The General at various film festivals until heart issues prevented her from traveling. In 1978, Mack suffered two heart attacks. Marion Mack appeared in the documentary series Hollywood (1980) in which she discussed her experience filming The General. Mack met producer Lewis Lewyn after winning a beauty contest at the Thomas H. Ince Studios. They married in 1923 and had one son, Lannie. Mack and Lewyn remained married until Lewyn’s death in 1969. On May 1, 1989, Marion Mack died of heart failure in Costa Mesa, California at the age of 87. After a private funeral, Mack was buried in Pacific View Memorial Park in Corona del Mar, Newport Beach.