Marius Casadesus (October 24, 1892 – October 13, 1981) was a French violinist and composer. He was the brother of Henri Casadesus, uncle of the famed pianist Robert Casadesus, and grand-uncle to Jean Casadesus. Casadesus' brother Henri was also a noted author of musical hoaxes, such as "Handel's Viola concerto in b-minor" and "J.C. Bach's Viola Concerto in c-minor." Casadesus is also known for having given the first recital of Ravel's "Tzigane" in the presence of the composer in Barcelona.