Her reputation rests on 66 detective novels and 15 short-story collections that have sold over two billion copies, an amount surpassed only by the Bible and the works of William Shakespeare.

[2][3] Her works contain several regular characters with whom the public became familiar, including Hercule Poirot, Miss Marple, Tommy and Tuppence Beresford, Parker Pyne and Harley Quin.

[4] Following the publication of the 1975 novel Curtain, Poirot's obituary appeared on the front page of The New York Times.

[8] One of Christie's plays, The Mousetrap, opened in West End theatre in 1952, and ran continuously until 16 March 2020, when the stage performances had to be temporarily discontinued during the COVID-19 pandemic.

Her biographer, Janet Morgan, reports that "archaeologists have celebrated ... [Christie's] contribution to Near Eastern exploration".

Four short stories, including "The Submarine Plans," "Christmas Adventure," "The Mystery of the Baghdad Chest," and "The Second Gong," were expanded into longer stories by Christie (respectively "The Incredible Theft," "The Adventure of the Christmas Pudding," "The Mystery of the Spanish Chest," and "Dead Man's Mirror").