Franz Theodor Reizenstein (7 June 1911 – 15 October 1968) was a German-born British composer and concert pianist. He left Germany for sanctuary in Britain in 1934 and went on to have his career there, including teaching at the Royal Manchester College of Music and Boston University, as well as performing.
Franz Reizenstein's parents were Dr. Albert Reizenstein (1871–1925) and Lina Kohn (b. 1880), both of Nuremberg, Germany. The family was Jewish and counted many professionals, scientists, bankers, and musically inclined people among its members.
Reizenstein grew up in Nuremberg and was considered a child prodigy. He composed his first pieces when he was 5, and by the age of 17 he had written a string quartet. His well-to-do and artistic family encouraged him to play chamber music at home. Eventually he was sent to study under Paul Hindemith at the Berliner Hochschule für Musik.
In 1934 he emigrated to England at the age of 23 to escape the Nazis, one of nearly 70 Jewish composers to do so from 1933–1945. Once in England, he furthered his studies under Ralph Vaughan Williams at the Royal College of Music, and began to incorporate English music into his works. He also studied the piano for eleven years with Solomon Cutner. He eventually became a professor at the Royal Academy of Music and the Royal Northern College of Music (then the Royal Manchester College of Music) in Manchester. Amongst his pupils at the Royal Academy of Music was Philip Martin whom he taught piano and composition. His compositional posts were extended when he was invited for six months as a Visiting Professor of Composition at Boston University in the United States, where there were also special concerts given of his works.