Fausto (Faust) is an 1831 Italian opera semiseria in four acts by French composer Louise Bertin. It was premiered on 7 March 1831 by the Théâtre-Italien in Paris, and ran for three performances. The premiere was sung in Italian, and acts 3 and 4 were combined into a single act 3 of two tableaux. Bertin had adapted the libretto from Goethe's Faust, Part One, writing it in French and commissioning Luigi Balocchi [ca], the Théâtre-Italien's chief librettist, to translate it into Italian. The premiere was originally planned for 1830 with the contralto Rosmunda Pisaroni intended for the title role but was postponed due to the revolution of July 1830. At the premiere, the role was transposed for tenor Domenico Donzelli.

Faust's laboratory with a window at the back overlooking a church

Scene 1. After a long life of study, Fausto is bored (Introduction: "Tutte volsi e rivolsi"/"All the twists and turns"). He sees no further meaning in his life and has prepared a poisoned chalice to end it (Aria: "Il vago sol del mondo"/"The faint sun of the world"). As he raises the chalice to his lips, church bells ring out, and a choir sings sacred songs, awakening memories of happier times (Scene with chorus: "Qual m'assorda rumor?"/"What noise deafens me?").

Scene 2. Faust's servant Wagner announces the arrival of a desperate young girl who needs his help.

Scene 3. Margarita, after some hesitation, reveals that a friend living with her is terminally ill (Trio (Fausto/Wagner/Margarita): "Vezzosa giovinetta"/"Pretty young girl"). She hopes that Fausto can heal her. Fausto, immediately captivated by Margarita's beauty, sets off with her.

Scene 4. Wagner watches them anxiously. He has not missed the way Fausto looked at the girl.

Scene 5. Upon his return, Fausto is inwardly distraught. He orders that no one be allowed into his room.

Scene 6. Fausto is obsessed with winning Margarita, even though his age seems to be an obstacle.