37) is an opera in two acts by Benjamin Britten, written for Kathleen Ferrier, who performed the title role.

Ronald Duncan based his English libretto on André Obey's play Le Viol de Lucrèce [fr].

The opera debuted in the United States on Broadway at the Ziegfeld Theatre in a production staged by Agnes de Mille which opened on 29 December 1948 and closed on 15 January 1949 after 23 performances.

The cast notably included Giorgio Tozzi as Tarquinius, Kitty Carlisle as Lucretia, Lidija Franklin as Bianca, Brenda Lewis as the Female Chorus, and Adelaide Bishop as Lucia.

[4] The Male and Female Choruses explain the situation in Rome: ruled by the foreigner Tarquinius Superbus and fighting off a Greek invasion, the city has sunk into depravity.

The previous night, a group of soldiers rode home unexpectedly to Rome to check on their wives, all of whom were caught betraying their husbands, with the single exception of Collatinus' wife Lucretia.

Junius, whose wife was among the faithless majority, goads young Tarquinius, the king's son, into testing Lucretia's chastity himself.