Jacobus Clemens non Papa (ca. 1510-ca. 1556) was a Flemish composer whose a cappella Masses, motets, and chansons represent high points in the history of Renaissance polyphonic vocal music.

Jacobus Clemens non Papa was born in Ypres, Flanders. Nothing is known of his education except that he was trained as a priest, and little is known about his career. He seems to have spent his early creative years in Paris, where his first works were published, but he returned to the Low Countries in 1540. It is known that he was in Bruges until 1545, where he served as priest and choirmaster of the children at St. Donatien. In subsequent years Clemens was active as a singer and composer at the cathedrals in Antwerp and's Hertogenbosch, at Ypres, and finally at Dixmuide, where he died and was buried.

Clemens published under the name Jacques Clément or Jacobus Clemens until...