Antonio de Ulloa was born in Seville, Spain, into an aristocratic and intellectually distinguished family. His father, Bernardo de Ulloa, was noted for his writings on economics. His brother Fernando would become an engineer and the chief of works of the Canal de Castilla.  Destined for a naval career, at the age of thirteen Antonio embarked in Cádiz on the galleon San Luis, bound for the port of Cartagena de Indias (in present-day Colombia).  After returning to Cádiz, Antonio entered the Real Compañía de Guardias Marinas (the Spanish Naval Academy) in 1733.