Richard Roy Douglas (12 December 1907 – 23 March 2015), better known as Roy Douglas, was a British composer, pianist and arranger. He worked as musical assistant to Ralph Vaughan Williams, William Walton, and Richard Addinsell, made well-known orchestrations of works such as Les Sylphides (based on piano pieces by Chopin) and Addinsell's Warsaw Concerto, and wrote a quantity of original music.