Poul Rovsing Olsen (November 4, 1922 – July 2, 1982) was a Danish composer and ethnomusicologist. Olsen was born in Copenhagen. He studied with Knud Jeppesen at the Copenhagen Conservatory (1943-6) and with Nadia Boulanger and Olivier Messiaen in Paris (1948-9), then worked in Copenhagen as a music critic. His early works showed the influences of Bela Bartók, Igor Stravinsky and Carl Nielsen, joined in the 1950s by 12-note serialism, but from the 1960s his music began to reflect his work as a musical ethnologist (A L′inconnu for voice and 13 instruments, 1962): he did fieldwork in Greenland and the Persian Gulf and taught at the universities of Lund (1967-9) and Copenhagen (from 1969). His output includes opera, orchestral and chamber music, piano pieces and songs.