Agatha Christie, in full Dame Agatha Mary Clarissa Christie, née Miller, (born September 15, 1890, Torquay, Devon, England—died January 12, 1976, Wallingford, Oxfordshire), English detective novelist and playwright whose books have sold more than 100 million copies and have been translated into some 100 languages.

Educated at home by her mother, Christie began writing detective fiction while working as a nurse during World War I. Her first novel, The Mysterious Affair at Styles (1920), introduced Hercule Poirot, her eccentric and egotistic Belgian detective; Poirot reappeared in about 25 novels and many short stories before returning to Styles, where, in Curtain (1975), he died. The elderly spinster Miss Jane Marple, her other principal detective figure, first appeared in Murder at the Vicarage (1930). Christie’s first major recognition came with The Murder of Roger Ackroyd (1926), which was followed by some 75 novels that usually made best-seller lists and were serialized in popular magazines in England and the United States.

Christie’s plays included The Mousetrap (1952), which set a world record for the longest continuous run at one theatre (8,862 performances—more than 21 years—at the Ambassadors Theatre, London) before moving in 1974 to St Martin’s Theatre, where it continued without a break until the COVID-19 pandemic closed theatres in 2020, by which time it had surpassed 28,200 performances; and Witness for the Prosecution (1953), which, like many of her works, was adapted into a successful film (1957). Other notable film adaptations included And Then There Were None (1939; film 1945), Murder on the Orient Express (1933; film 1974 and 2017), Death on the Nile (1937; film 1978), and The Mirror Crack’d From Side to Side (1952; film [The Mirror Crack’d] 1980). Her works were also adapted for television.

In 1926 Christie’s mother died, and her husband, Colonel Archibald Christie, requested a divorce. In a move she never fully explained, Christie disappeared and, after several highly publicized days, was discovered registered in a hotel under the name of the woman her husband wished to marry. In 1930 Christie married the archaeologist Sir Max Mallowan; thereafter she spent several months each year on expeditions in Iraq and Syria with him. She also wrote romantic nondetective novels, such as Absent in the Spring (1944), under the pseudonym Mary Westmacott. Her Autobiography (1977) appeared posthumously. She was created a Dame Commander of the Order of the British Empire in 1971.