American dancer and choreographer who further developed the narrative aspect of dance and made innovative use of American themes, folk dances, and physical idioms in her choreography of musical plays and ballets.

Her father was the playwright William Churchill DeMille, her mother the daughter of the economist Henry George (George, Henry), and her uncle the film director Cecil B. DeMille (DeMille, Cecil B.). She spent her youth (from 1914) in Hollywood and earned a B.A. degree in English from the University of California, Los Angeles. She also learned dance. After moving to New York City, she toured the United States and Europe (1929–40), giving concerts of her own character sketches in mime-dance. She created her first major roles in ballet with the Ballet Rambert, performing in works by Antony Tudor (Tudor, Antony), and later studied modern dance.

Rodeo (1942), one of her most important ballets, was created for the Ballet Russe de Monte Carlo. The first ballet to include tap dancing, it used distinctively American gestures—bronco-riding and steer-roping movements. Most of de Mille's other ballets were choreographed for New York City's Ballet Theatre, which she joined in 1940. Her works for that company include Fall River Legend (1948; based on the story of Lizzie Borden (Borden, Lizzie)), The Harvest According (1952), and Three Virgins and a Devil (1941).

De Mille's equally outstanding career as a choreographer of musicals (musical) began in 1929 with The Black Crook. In 1943 she choreographed the dances for Oklahoma!. In that Broadway musical, dance not only added to the dramatic atmosphere but also, for the first time in American theatrical history, was instrumental in advancing the plot. Among the other musicals for which she staged the dances were One Touch of Venus (1943), Carousel (1945), Brigadoon (1947), Gentlemen Prefer Blondes (1949), Paint Your Wagon (1951), The Girl in Pink Tights (1954), and 110 in the Shade (1963). She also arranged dances for the films Romeo and Juliet (1936) and Oklahoma! (1955), directed plays, and choreographed television programs.

The recipient of many prizes and awards, de Mille continued to choreograph ballets for the American Ballet Theatre, including A Rose for Miss Emily (1971), Texas Fourth (1976), and The Informer (1988). Among her several books are Dance to the Piper (1952), To a Young Dancer (1962), The Book of the Dance (1963), Lizzie Borden: A Dance of Death (1968), and Speak to Me, Dance with Me (1973). She also wrote two autobiographies, And Promenade Home (1958) and Where the Wings Grow (1977). Her later books include her controversial biography of fellow dancer-choreographer Martha Graham (Graham, Martha) entitled Martha (1991).