José del Castillo Sáez de Tejada or José Castillo (29 June 1901, Alcalá la Real – 12 July 1936, Madrid) was a Spanish Police Guardia de Asalto (Assault Guard) lieutenant during the Second Spanish Republic.
His murder by four Falangist gunmen on July 12, 1936 led to a sequence of events that helped precipitate the Spanish Civil War.