Betrothal in a Monastery (original Russian title Обручение в монастыре; Obrucheniye v monastïre), Op. 86 is an opera by Sergei Prokofiev, his sixth with an opus number. The libretto, in Russian, was by the composer and Mira Mendelson (his companion in later life), after Richard Brinsley Sheridan's ballad opera libretto for Thomas Linley the younger's The Duenna.

Librettist Sergei Prokofiev and Mira Mendelson (Based on "The Duenna" by Richard Brinsley Sheridan)
Date of composition 1943 (1940-1943)
Premiered 1946, November 3rd (Kirov Theatre) in Saint Petersburg, Russia
Type Opera
Catalogue Op. 86
Instruments Voice (Tenor) - Don Jerome
Voice (Baritone) - Don Ferdinand, son of Don Jerome
Voice (Soprano) - Louisa, daughter of Don Jerome
Voice (Mezzo-Soprano) - The Duenna
Voice (Tenor) - Don Antonio
Voice (Mezzo-Soprano) - Clara d'Almanza
Voice (Bass) - Mendoza, a fish merchant
Voice (Baritone) - Don Carlos, friend of Mendoza
Voice (Bass) - Padre Augustin
Voice (Tenor) - Father Elustaf
Voice (Bass) - Father Chartreuse
Voice (Bass) - Father Benedictine
Voice (Soprano) - Lauretta
Voice (Soprano) - Rosina
Voice (Tenor) - Lopez
Orchestra
Autotranslations beta Sergueï Prokofiev: Betrothal in a Monastery, Op. 86
Sergej Sergeevič Prokof'ev: Betrothal in a Monastery, Op. 86
Sergei Sergejewitsch Prokofjew: Betrothal in a Monastery, Op. 86