Louis-Ferdinand Céline ( say-LEEN, French: [selin] (listen)) was the pen name of Louis Ferdinand Auguste Destouches (pronounced [detuʃ]; 27 May 1894 – 1 July 1961), a French novelist, pamphleteer and physician. He developed a new style of writing that modernized French literature. His most famous work is the 1932 novel Journey to the End of the Night.

Céline used a working-class, spoken style of language in his writings, and attacked what he considered to be the overly polished, "bourgeois" language of the "academy". His works influenced a broad array of literary figures, not only in France but also in the English-speaking world and elsewhere in the Western World; this includes authors associated with modernism, existentialism, black comedy and the Beat Generation.

Céline's vocal support for the Axis powers during the Second World War and his authorship of antisemitic and pro-fascist pamphlets has complicated his legacy as cultural icon.