Pérotin (fl. c. 1200) was a European composer, believed to be French, who lived around the end of the twelfth and beginning of the thirteenth century. He was the most famous member of the Notre Dame school of polyphony. He was one of very few composers of his day whose name has been preserved, and can be reliably attached to individual compositions; this is due to the testimony of an anonymous English student at Notre Dame known as Anonymous IV, who wrote about him. Anonymous IV called him Perotin Magister, which means Pérotin the master or expert. The name Pérotin is itself derived from Perotinus, the Latin diminutive of Petrus, the Latin version of the French name Pierre (just as Léonin comes from Leoninus, the Latin diminutive of Léo).
Works attributed to Pérotin include the four-voice Viderunt omnes and Sederunt principes; the three-voice Alleluia, Posui adiutorium, Alleluia, Nativitas, and nine others attributed to him by contemporary scholars on stylistic grounds, all in the organum style; the two-voice Dum sigillum summi Patris, and the monophonic Beata viscera in the conductus style. (The conductus sets a rhymed Latin poem called a sequence to a repeated melody, much like a contemporary hymn.)
Pérotin's works are preserved in the Magnus Liber, the Great Book of early polyphonic church music, which was in the collection of the cathedral of Notre Dame in Paris. The Magnus Liber also contains the works of his slightly earlier contemporary Léonin. However, attempts by scholars to place Pérotin at Notre Dame have been inconclusive, all evidence being circumstantial, and very little is known of his life.