Faust is a grand opera in five acts by Charles Gounod to a French libretto by Jules Barbier and Michel Carré from Carré's play Faust et Marguerite, in turn loosely based on Johann Wolfgang von Goethe's Faust, Part 1. It debuted at the Théâtre Lyrique on the Boulevard du Temple in Paris on 19 March 1859.

Faust was rejected by the Paris Opera, on the grounds that it was not sufficiently "showy", and its appearance at the Théatre-Lyrique was delayed for a year because Adolphe d'Ennery's drama Faust was playing at the Porte St. Martin. The manager Léon Carvalho (who cast his wife Marie Miolan-Carvalho as Marguerite) insisted on various changes during production, including cutting several numbers.

Faust was not initially well received. The publisher Antoine Choudens, who purchased the copyright for 10,000 francs, took the work (with added recitatives replacing the original spoken dialogue) on tour through Germany, Belgium, Italy and England, with Marie Miolan-Carvalho repeating her role.

It was revived in Paris in 1862, and was a hit. A ballet had to be inserted before the work could be played at the Opéra in 1869: it became the most frequently performed opera at that house and a staple of the international repertory, which it remained for decades, being translated into at least 25 languages.

Its popularity and critical reputation have declined somewhat since around 1950. A full production, with its large chorus and elaborate sets and costumes, is an expensive undertaking, particularly if the act 5 ballet is included. However, it appears as number 35 on the Operabase list of the most-performed operas worldwide.

It was Faust with which the Metropolitan Opera in New York City opened for the first time on 22 October 1883. It is the eighth most frequently performed opera there, with 747 performances through the 2011-2012 season. It was not until the period between 1965 and 1977 that the full version was performed (and then with some minor cuts), and all performances in that production included the Walpurgisnacht and the ballet.