Mari Blanchard was born on April 13, 1927 in Long Beach, California. A polio victim at age 9, Blanchard’s health eventually improved enough that she ran away from home and joined a circus in her teens. She then attended the University of Southern California, getting her degree. In the late 1940s, Blanchard became a successful print model and film extra. Blanchard began appearing in films after she was seen by a producer in an advertisement for bubble bath in 1950. Blanchard found limited success as an actress. From 1951 to 1952, she took small roles in a number of films at MGM, RKO, and Paramount, until she was signed by Universal-International in 1952. Her first film at the studio was Back at the Front (1952). She co-starred with Victor Mature in a 1953 adventure movie, The Veils of Bagdad. One of her most memorable roles was the Venusian queen, Allura, in the 1953 comedy Abbott and Costello Go to Mars. She starred in Destry (1954), a western with Audie Murphy, reprising a role that Marlene Dietrich had played in the story’s original version, Destry Rides Again, but changing the character’s name from “Frenchy” to “Brandy.” In 1955, she appeared in “Escape From Fear”, an episode of the television series Climax!. She also was featured in Son of Sinbad (1955) and The She Devil (1957). An attack of appendicitis during the filming of The She Devil landed Blanchard in the hospital.

In the 1960–1961 television season, Blanchard starred as Kathy O’Hara in the NBC Western series Klondike with Ralph Taeger, James Coburn, and Joi Lansing. She also appeared as Margarita Colinas with Cesar Romero in the Rawhide episode “Incident of the Stalking Death”. In 1962, she guest starred as murder victim Irene Chase in a Perry Mason episode, “The Case of the Melancholy Marksman.” In 1963, she had a small but flamboyant role in a John Wayne film, McLintock!. Blanchard was married three times, to lawyer Reese Hale Taylor, then to George Shepard (1965-66) and Vincent J. Conti (1967-70). After abandoning her film career upon the release of her final film, McLintock! in 1963, Blanchard retired, acting in just a few TV programs afterward. She was diagnosed with cancer in the 1960s. Following a long struggle she died at the age of 43 in Woodland Hills, California.