Bogusław Schaeffer (born 6 June 1929, Lwów, Poland (now Lviv, Ukraine) – died 1 July 2019) was a Polish composer, a music theorist and a teacher. In Kraków he studied musicology with Jachimecki at the university (1949–53) and composition with Malawski at the State Higher School of Music. He was a music critic between 1953-59, but from then onwards devoted his time primarily to composition and teaching. He taught at the Kraków Academy from 1963.

As a composer, he rapidly became the most fearless Polish proponent of new technical and aesthetic boundaries, particularly with regard to notation and performance practice with over 400 works to his name.