Petrus Wilhelmi de Grudencz (1392–1480) was a Polish composer, music theorist, and painter of the Renaissance. His work is very abundant, and he created more than 200 works, including choral hymns, oriental music pieces and instrumental music. Petrus Wilhelmi de Grudencz is known as one of the first Polish composers to use mensural notation and the new notation, which had a great influence on the development of music not only in Poland but worldwide.
