After studying medicine, in 1929 Mayo made his debut in the theatre with the company of Ernesto Vilches. He fought for Francisco Franco in the Spanish Civil War in aviation. He starred in propaganda films such as Escuadrilla (1941), Harka (1941), A mí la legión (1942) but is perhaps best known for Raza, written by Francisco Franco under the name of Jaime de Andrade.