Antonius Wilhelmus Adrianus de Leeuw (Rotterdam, 16 November 1926 - Paris, 31 May 1996) was a Dutch composer. He occasionally experimented with microtonality.Taught by Henk Badings, Olivier Messiaen and others, and in his youth influenced by Béla Bartók, De Leeuw was a teacher at the University of Amsterdam and later professor of composition and electronic music at the Sweelinck Conservatory in Amsterdam from 1959 to 1986, at which institute he served as director from 1971–73. For his notable students, See: List of music students by teacher: K to M#Ton de Leeuw.