Reginald Foresythe (28 May 1907 – 28 December 1958) was a British jazz pianist, arranger, composer, and bandleader known for his unique contributions to the jazz music scene during the early to mid-20th century. Born in London, Foresythe was the son of a West African barrister of Sierra Leone Creole descent and an Englishwoman of German descent. His musical journey began at the age of eight when he started playing the piano.

In the late 1920s, Foresythe worked as a pianist and accordionist in dance bands across Paris, Australia, Hawaii, and California. He also composed music for films by D. W. Griffith and played with Paul Howard's Quality Serenaders. By 1930, he had moved to Chicago, where he wrote arrangements for Earl Hines and music for Paul Whiteman. His compositions were recorded by notable artists such as Louis Armstrong, Fats Waller, and Adrian Rollini.

Foresythe's career took him to New York City in the mid-1930s, where he arranged for Whiteman and recorded with Benny Goodman, John Kirby, and Gene Krupa. Returning to London, he formed a studio recording group called "The New Music of Reginald Foresythe," producing works like "Serenade to a Wealthy Widow" and "Garden of Weed." His recordings were distinctive for their use of reeds and saxophones, omitting brass instruments.

During World War II, Foresythe served in the Royal Air Force and entertained troops with his performances. Post-war, he struggled with "war nerves" (now recognized as PTSD) and alcoholism, which affected his later career. Despite these challenges, he continued to perform in London clubs during the 1950s.

Foresythe was openly gay and known for his involvement in altercations in gay clubs and bars. He collaborated with songwriters Andy Razaf and Ted Weems, contributing to pieces like "Be Ready" and "Please Don't Talk About My Man." Reginald Foresythe passed away in 1958 after a fall, leaving behind a legacy of innovative jazz compositions and arrangements.