Born in Bombay, India to an Anglo-Irish father and an Anglo-Sinhalese mother, Constance Selby, who gave birth to Merle at the age of 15 and allowed her to be raised as her sister, Merle came to England for the first time in 1928. Initially she worked as a club hostess under the name Queenie O'Brien and played in minor and unbilled rolls in various films. Her first major film role was as Anne Boleyn in The Private Life of Henry VIII (1933). In 1934, she played the female lead in The Scarlet Pimpernel, opposite Leslie Howard.
Oberon's career went on to greater heights partly as a result of her relationship with and later marriage to director Alexander Korda, who had persuaded her to take the name under which she became famous. She was to star in his film of I, Claudius (1937) as Messalina, but a serious car accident resulted in filming being abandoned. Merle Oberon was scarred for life, but skilled lighting technicians prevented her injuries being spotted by cinema audiences. She went on to appear as Cathy in Wuthering Heights (1939), as George Sand in A Song to Remember (1945), and as Empress Josephine in Désirée (1954). During her time as a film star, Oberon went to great lengths to disguise her mixed-race background and when her dark-skinned mother moved in with her in Hollywood, she masqueraded as Oberon's maid.
Merle Oberon divorced Sir Alexander Korda in 1945, to marry cinematographer Lucien Ballard. She married twice more, to Italian-born Mexican industrialist Bruno Pagliai (two adopted children) and Dutch actor Robert Wolders, before her retirement to Malibu, California, where she died after suffering a stroke.