Juan José Castro (March 7, 1895 – September 3, 1968) was an Argentine composer and conductor.

Born in Avellaneda, Castro studied piano and violin under Manuel Posadas and composition under Eduardo Fornarini, in Buenos Aires. In the 1920s he was awarded the Europa Prize, and then went on to study in Paris at the Schola Cantorum under Vincent d'Indy and Édouard Risler. Returning to Buenos Aires in 1925, he was named conductor of the Renacimiento Chamber Orchestra in 1928 and the Teatro Colón in 1930. From 1939 to 1943 he was a professor at the Buenos Aires Conservatory.