Valentin Louis Georges Eugène Marcel Proust (10 July 1871 - 18 November 1922), better known as Marcel Proust, was a French novelist, critic, and essayist best known for his monumental novel À la recherche du temps perdu (In Search of Lost Time; earlier rendered as Remembrance of Things Past), published in seven parts between 1913 and 1927: Swann's Way, In the Shade of Blooming Young Girls, The Guermantes Walk, Sodom and Gomorrah, The Captive Girl, Vanished Albertine, and Time Found Again. He is considered by English critics and writers to be one of the most influential authors of the 20th century.

Begun in 1909, when Proust was 38 years old, À la recherche du temps perdu consists of seven volumes. Graham Greene called Proust the "greatest novelist of the 20th century", and W. Somerset Maugham called the novel the "greatest fiction to date." Proust died before he was able to complete his revision of the drafts and proofs of the final volumes, the last three of which were published posthumously and edited by his brother, Robert.

The book was translated into English by C. K. Scott Moncrieff, appearing under the title Remembrance of Things Past between 1922 and 1931. Scott Moncrieff translated volumes one through six of the seven volumes, dying before completing the last. This last volume was rendered by other translators at different times. The title In Search of Lost Time, a literal rendering of the French, has gained usage in modern times.