Claude Debussy's Préludes are 24 pieces for solo piano, divided into two books of 12 preludes each. Unlike some notable collections of preludes from prior times, such as Chopin's Op. 28 preludes, or the preludes from Johann Sebastian Bach's The Well-Tempered Clavier, Debussy's do not follow a strict pattern of tonal centers.

Each book was written in a matter of months, at an unusually fast pace for Debussy. Book I was written between December 1909 and February 1910, and Book II between the last months of 1912 and early April 1913.

On 3 May 1911, pianist Jane Mortier (to whom works were dedicated by Bohuslav Martinů^[1] and Erik Satie) premiered the first book of preludes at the Salle Pleyel in Paris.^[2] German-English pianist Walter Morse Rummel, a student of Leopold Godowsky, premiered the second book in 1913 in London.^[2]

Debussy and other pianists who gave early performances of the preludes (including Ricardo Viñes) played them in groups of three or four, which remains a popular approach today. This allows performers to choose preludes with which they have the strongest affinity, or those to which their particular gifts are most suited.

There is a strong tonal relationship between the preludes that suggests that their published order is not arbitrary.^[3] For example, the first three preludes of the first book (Danseuses de Delphes, Voiles, and Le Vent dans la Plaine) make continued references to the key of B♭.^[3] Although these references come and go, it creates a strong sense of fluidity and connection between these preludes.

The order of the preludes is not considered imperative (as it is with Chopin's preludes, for example). Several pianists have performed them out of order; and at least one recording, by Ivan Ilić, changes the order entirely.^[4]

The first complete recording of both books was made in England in 1938 by South African pianist Adolph Hallis.^[5]

In the original editions, Debussy had the titles placed at the end of each work,^[6] allowing performers to experience each prelude without being influenced by its titles beforehand.

Two of the titles were set in quotation marks by Debussy because they are, in fact, quotations: «Les sons et les parfums tournent dans l'air du soir» is from Charles Baudelaire's poem Harmonie du soir ("Evening Harmony"), from his volume Les Fleurs du mal.^[7] «Les fées sont d'exquises danseuses» is from J. M. Barrie's book Peter Pan in Kensington Gardens, which Debussy's daughter had received as a gift.

At least one title is poetically vague: The exact meaning of Voiles, the first book's second prelude, is impossible to ascertain; in French, voiles can mean either "veils" or "sails".^[8]

Numerous orchestrations have been made of the various preludes, mostly of La fille aux cheveux de lin and La cathédrale engloutie. Complete orchestrations of all 24 preludes include versions by Pavica Gvozdić, Peter Breiner, Luc Brewaeys, Hans Henkemans and Colin Matthews.^{[9][10][11][12]} Sean Osborn and conductor Noam Zur have orchestrated the first book.^[13][14]

Some of the Préludes were adapted to form the dynamic soundtrack of Untitled Goose Game.^[15][16]