Owen was born George Owen Smith in Hackney, London, and began playing the saxophone at the age of 15. He played in local groups such as Teddy Joyce's Juveniles and the Royal Kiltie Juniors, before founding his own ensemble whilst still in his teens. He studied with Benny Glassman and then attended the Royal College of Music. During World War II he played in the Bomber Command Band of the RAF, then arranged for Ted Heath and Cyril Stapleton after 1945. In 1954, he had his name legally changed to Reginald Owen. He published a book, the Reg Owen Arranging Method, in 1956, and began writing film scores in 1957, including the scores to Date with Disaster, (1957), There's Always a Thursday, (1957), Payroll (1961) and Very Important Person (1961). In 1959, he even scored a Top 40 hit in the U.S. with "Manhattan Spiritual", which peaked at #10 on the Billboard Hot 100. The same track reached #20 in the UK Singles Chart in March 1959. A further track, "Obsession", peaked at #43 in the UK in October 1960.
In 1961 Owen moved to Brussels, working as a composer, conductor, and arranger throughout continental Europe. He moved to Spain in the 1970s, and died at the Clinica Limonar in Málaga, on 23 May 1978 at the age of 57.