Félix de Azara (1746-1821) was a Spanish explorer and naturalist. His scientific work in South America showed a marked advance over that of any predecessor in the regions he visited.

Félix de Azara was a native of Barbuñales in the Spanish province of Huesca. He attended a mathematical school at Barcelona and in 1767 became an army lieutenant with an engineering specialty. In 1775 he took part in the disastrous Spanish attack on Algiers commanded by Alejandro O'Reilly and received a promotion, as well as a severe chest wound.

In 1777 Spain signed the Treaty of San Ildefonso with Portugal, followed by the Peace of El Pardo a year later, by which the two countries agreed that military commissions should survey and determine the joint boundary of their South American possessions. Azara was assigned to the Spanish delegation headed by José Varela y Ulloa...