Mefistofele is an opera in a prologue and five acts, later reduced to four acts and an epilogue, the only completed opera with music by the Italian composer-librettist Arrigo Boito. The opera was given its premiere on 5 March 1868 at La Scala, Milan, under the baton of the composer, despite his lack of experience and skill as a conductor.

Arrigo Boito was an Italian librettist, composer, poet and critic whose only completed opera was Mefistofele. Among the operas for which he wrote the libretti are Giuseppe Verdi's monumental last two operas Otello and Falstaff as well as Amilcare Ponchielli's La Gioconda.