Antonio de Ulloa y de la Torre-Guiral (12 January 1716 – 3 July 1795) was a Spanish Navy officer. He spent much of his career in the Americas, where he carried out important scientific work. As a scientist, Ulloa is regarded as one of the major figures of the Enlightenment in Spain. As a military officer, Ulloa achieved the rank of vice admiral. He also served the Spanish Empire as an administrator in the Viceroyalty of Peru and in Spanish Louisiana.
At the age of nineteen, Ulloa joined the French Geodesic Mission to the Equator, which established that the shape of the Earth is an oblate spheroid, flattened at the poles, as predicted by Isaac Newton. The mission took more than eight years to complete, during which time Ulloa, in close collaboration with his fellow naval officer Jorge Juan, made many astronomical, natural, and social observations in South America. Ulloa and Juan also helped to organize the defense of the Peruvian coast against the English squadron of Commodore Anson, after the outbreak of the War of Jenkins' Ear in 1739.
