Derek Wadsworth (5 February 1939 – 3 December 2008) was an English jazz musician, composer, and arranger. Wadsworth played in bands in Huddersfield in the late 1950s. He was based in London from the early 1960s and played in several bands. He was musical director for singer Dusty Springfield in the mid-1960s, and for a Diana Ross world tour, and held the same position in the musical Hair for five years from 1968. He first arranged music in 1970, for Spring and Port Wine. As a musician, he toured Europe with Georgie Fame and was with Humphrey Lyttelton into the mid-1970s. Wadsworth toured the United States with Maynard Ferguson in 1972, as well as recording with the bandleader. He also had lengthy periods in the 1970s with Graham Collier and John Dankworth. Wadsworth founded the Musicians Union's Rock Workshop and lectured there in the latter part of the decade. He also led his own sextet. In 1975, he arranged for Alfie Darling and in the following year, he composed and arranged for Space: 1999 (including the second series's newly-composed main theme) and worked on the film The Man Who Fell to Earth.