Alexandre-Marie Quesnay de Beaurepaire (1755–1820) was the grandson of French philosopher and economist, François Quesnay, and was among the idealistic French contingency who joined in the American struggle for independence during the late 18th century.
De Beaurepaire is best known for occupying several positions: a captain in the Royal Guards of Louis XVI, French captain (with residence in Virginia) in the American Revolutionary War Army (April 1777 – 1778) and co-patron, alongside Thomas Jefferson, of the short-lived first United States Academy of Science & Arts in Richmond, Virginia.