Her debut in the British film, Contraband, in 1940 was left on the cutting room floor. But that was followed by a series of other films and it was her role as a troubled nun in Michael Powell's Black Narcissus in 1947 which brought her to the attention of Hollywood producers.

Although the Scottish pronunciation of her surname is straightforward, when she was being promoted as a Hollywood actress, her last name was pronounced the same as "car". In order to avoid confusion over pronunciation, the slogan "Kerr rhymes with Star" was used.

Her "English" accent and manner led to a succession of roles, of which the only real departure from stereotype was in From Here to Eternity (1953) in which she was nominated for an Oscar for Best Actress. Her most famous roles were as the governess Anna Leonowens in the film version of the Rodgers and Hammerstein musical The King and I and for her role opposite Cary Grant in An Affair to Remember. A stage actress, in 1955 she won the Sarah Siddons Award for her work in Chicago theatre. In 1969, she appeared nude in John Frankenheimer's The Gypsy Moths.

She experienced a career resurgence in the early 1980s playing Emma Harte in the television adaptation of Barbara Taylor Bradford's A Woman of Substance.

Deborah Kerr has been married twice. First, on 28 November 1945, she married Squadron Leader Anthony Bartley. They had two daughters, Melanie Jane, born on 27 December 1947 and Francesca Ann. She and Bartley divorced in 1959. On 23 July 1960, she married writer Peter Viertel.

For her contributions to the motion picture industry, Deborah Kerr has a star on the Hollywood Walk of Fame at 1709 Vine Street.

In 1998 she was appointed a Commander of the British Empire.

She suffers from Parkinson's disease at home in Switzerland where she has long resided.