Miserere is a setting of Psalm 51 by Italian composer Gregorio Allegri. It was composed during the reign of Pope Urban VIII, probably during the 1630s, for the exclusive use of the Sistine Chapel during the Tenebrae services of Holy Week, and its mystique was increased by unwritten performance traditions and ornamentation. It is written for two choirs, of five and four voices respectively, singing alternately and joining to sing the ending in one of the most recognised and enduring examples of polyphony, in this case in a 9-part rendition.

Psalm 51, one of the penitential psalms, is the 51st psalm of the Book of Psalms, beginning in English in the King James Version: "Have mercy upon me, O God". In the slightly different numbering system used in the Greek Septuagint and Latin Vulgate translations of the Bible, this psalm is Psalm 50. In Latin, it is known as Miserere, in Ancient Greek: Ἥ Ἐλεήμων, romanized: Hḗ Eleḗmōn), especially in musical settings. The introduction in the text says that it was composed by David as a confession to God after he sinned with Bathsheba.