Paul Horn began playing the piano at the age of four, the clarinet at ten, and the saxophone at twelve. He studied the clarinet and flute at the Oberlin Conservatory of Music in Ohio, earning a bachelor's degree. He gained a master's degree from the Manhattan School of Music.
Moving to Los Angeles he played with Chico Hamilton's Quintet from 1956 to 1958 and recorded his debut album Something Blue in 1960. By now an established West Coast session player he played on the Duke Ellington Orchestra's Suite Thursday and worked with Nat King Cole, Tony Bennett and others. In 1970, he moved with his second wife Tryntje and two sons Marlen and Robin from his first marriage to Victoria, British Columbia on Vancouver Island. He formed his own quintet and has recorded film scores for the National Film Board of Canada.
He was known for his innovations on both metal and traditional wooden flutes. Best known of his albums are his Inside recordings, which feature airy, echoing sounds created in places of spiritual importance. The series began with Horn sneaking a tape recorder into the Taj Mahal during a trip to India in 1968, (released as Inside) where he was with The Beatles at Rishikesh, and continued later with recordings inside the Great Pyramid of Giza, and a return to the Taj Mahal in 1989. Horn later made similar recordings in a cathedral, in the canyons of the Southwestern United States with Native American flautist R. Carlos Nakai, and with Orcas.