William Cornysh (born, East Greenwich, England—died c. October 1523, Hylden?, Kent) was an English composer, poet, playwright, and actor, a favourite court musician of Henry VIII, who granted him a manor in Kent, where he presumably died.
Little is known of Cornysh’s early life, but he may have been the son of William Cornysh (died c. 1502), the first master of the choristers at Westminster (about 1479–91) and a Gentleman of the Chapel Royal, a group that tutored young boys in the art of singing and acting. William Cornysh the younger was connected with the Chapel Royal from 1496 and in 1509 succeeded William Newark as master. He took the Chapel Royal to France with the king in 1513 and also again in 1520 to the Field of Cloth of Gold, where the group was favourably received. He wrote and performed in plays, masques, and pageants, being a principal actor at the court from 1508 to 1516. His musical works included four complete motets and a Magnificat, as well as a number of sacred and secular songs. A poem he wrote while in Fleet prison for slander was printed in a collection of the poet John Skelton’s works and is sometimes mistakenly attributed to that poet.