Eustoquio Antonio Díaz Vélez (Buenos Aires, November 2, 1782 - id., April 1, 1856), Argentine military who fought in the British Invasions of the Río de la Plata, participated in the May Revolution and fought in the war of independence and Argentine civil wars. His name was Eustoquio (Eustochio Antonio according to his baptismal certificate) but usually is cited, incorrectly, as Eustaquio.