Milton Mesirow (November 9, 1899 – August 5, 1972), better known as Mezz Mezzrow, was an American jazz clarinetist and saxophonist from Chicago, Illinois. He is remembered for organizing and financing recording sessions with Tommy Ladnier and Sidney Bechet. He recorded with Bechet as well and briefly acted as manager for Louis Armstrong. Mezzrow is equally known as a colorful character, as portrayed in his autobiography, Really the Blues (which takes its title from a Bechet composition), co-written with Bernard Wolfe and published in 1946.

According to one biographer: “As a juvenile delinquent, [Mezzrow] was in and out of reformatory schools and prisons where he was exposed to jazz and blues music. He began to play the clarinet and decided to adopt the African American culture as his own. He became a ubiquitous figure on the Chicago jazz scene of the 1920s and ran in the circles of musicians that included King Oliver, Louis Armstrong, Sidney Bechet, Jimmy Noone, Al Jolson, Baby Dodds, Bix Beiderbecke, Louis Bellson and many others. [He] was an advocate for the pure New Orleans jazz style.”