Francisco Antonio de Agurto y Salcedo, 1st Marquis of Gastañaga (Vitoria, 1640 – Zaragoza, November 2, 1702) was a Spanish nobleman, viceroy and governor of Basque origin. He became first Marquis de Gastañaga in 1676 and was Governor of the Habsburg Netherlands between 1685 and 1692. He led the Spanish troops in the Battle of Fleurus (1690) and unsuccessfully defended Mons against the French. He began a new royal chapel of Saint Joseph in Waterloo in 1687 an attempt to curry favour with the court, but was recalled to Madrid for his failure to hold Mons. After this he became Viceroy of Catalonia between 1694 and 1696, where he was confronted with a French invasion during the War of the Grand Alliance.
He never married. After his death, the title of Marquis of Gastañaga went to his brother, Iñigo Eugenio (1648–1715).