Fausta is a melodramma, or opera seria, in two acts by Gaetano Donizetti. The Italian libretto was partly written by Domenico Gilardoni, who died while doing so: the remainder was written by Donizetti. The literary source of the opera's libretto is Crispo, a tragedy improvised by Tommaso Sgricci on 3 November 1827.
The opera successfully debuted on 12 January 1832 at the Teatro di San Carlo in Naples, and was written with prima donna Giuseppina Ronzi de Begnis in mind; she was rumored to be the king's mistress.
Although the libretto had irked the chief censor, the production went ahead, supposedly because of Ronzi de Begnis' influence in high places. Donizetti wrote this opera for the birthday of King Ferdinand II of the Two Sicilies.