Born Deborah Jane Trimmer in Glasgow, Scotland in 1921, she was the daughter of a soldier who had been gassed in World War I. A shy, insecure child, she found an outlet for expressing her feelings in acting. Her aunt, a radio star, got her some stage work when she was a teenager, and she came to the attention of British film producer Gabriel Pascal, who cast her in his film version of George Bernard Shaw's "Major Barbara" (Major Barbara (1941)) and Love on the Dole (1941). She quickly became a star of the British cinema, playing such diverse roles as the three women in The Life and Death of Colonel Blimp (1943) and the nun in Black Narcissus (1947).

In 1947, she "crossed the pond" to Hollywood and came to MGM, where she found success in films like The Hucksters (1947), Edward, My Son (1949) and Quo Vadis (1951). After a while, however, she tired of playing prim-and-proper English ladies, so she made the most of the role of the adulteress who romps on the beach with Burt Lancaster in From Here to Eternity (1953). The film was a success, and Kerr received her second Oscar nomination. She also achieved success on the Broadway stage in "Tea and Sympathy", reprising her role in the 1956 film version of the same name. (Tea and Sympathy (1956)). That same year she played one of her best-remembered screen roles, "Mrs. Anna" in The King and I (1956). More success followed in Heaven Knows, Mr. Allison (1957), An Affair to Remember (1957), Separate Tables (1958), The Sundowners (1960), The Innocents (1961) and The Night of the Iguana (1964).

In 1968, she quit movies, appalled by the explicit sex and violence of the day. After some stage and TV work in the 1970s and 1980s and swan song performances in The Assam Garden (1985) and Hold the Dream (1986), she retired from acting altogether. Kerr holds the record for the most Academy Award nominations for Best Actress without a win (six), but that was made up for in 1994, when she was given an Honorary Oscar for her screen achievements.