Born in Oakland, California, he studied law at the University of California where he was a member of the California-Alpha chapter of Sigma Phi Epsilon fraternity, but showed greater interest in the campus' theatrical group. He moved to New York in 1923 and began work as a stage actor, as well as a costume and set designer. After some time in Greenwich Village, he moved back to California, this time to Hollywood, and found work as a movie extra. His acting work was short-lived, however, and he made a career change to costume and wardrobe. (He can be spotted dancing with Irene, another future top designer, in Erich von Stroheim's 1925 film "The Merry Widow".)
Plunkett's first credited work as a costume designer first appeared on screen in 1927, while working at RKO, on productions such as Vigil in the Night, starring Carole Lombard. He built a huge costume and wardrobe department into an efficient and creative studio asset. With free rein at that studio, he set about creating costumes that rivaled the work of his contemporaries, such as Travis Banton and Adrian.
Plunkett retired in 1966, after having worked in films, on Broadway and for the Metropolitan Opera. He spent the last years of his life with his partner Lee, whom he formerly adopted so that he could inherit his estate.
Information retrieved from wikipedia.com