Joseph von Hammer-Purgstall (June 9, 1774 – November 23, 1856) was an Austrian orientalist.
Born Joseph Hammer in Graz, Styria, he received his early education mainly in Vienna. Entering the diplomatic service in 1796, he was appointed in 1799 to a position in the Austrian embassy in Constantinople, and in this capacity he took part in the expedition under Admiral William Sidney Smith and General John Hely-Hutchinson against France. In 1807 he returned home from the East, after which he was made a privy councillor. In 1835, upon inheriting the estates of the Countess Purgstall, he acquired the title Freiherr.
For fifty years Hammer-Purgstall wrote prolifically on the most diverse subjects and published numerous texts and translations of Arabic, Persian and Turkish authors. By traversing so large a field, he lay himself open to the criticism of specialists, and he was severely handled by Friedrich Christian Diez (1794–1876), who, in his Unfug und Betrug (1815), devoted to him nearly 600 pages of abuse. He also came into friendly conflict on the subject of the origin of The Thousand and One Nights with his younger English contemporary Edward William Lane.
Hammer-Purgstall's principal work is his Geschichte des osmanischen Reiches (10 vols., 1827–1835). Among his other works are
Hammer-Purgstall supported the foundation of the Austrian Academy of Sciences in Vienna and became the Academy's first president (1847–1849). The Austrian Oriental Society, founded in 1959 to foster cultural relations with the Near East, is formally named 'Österreichische Orient-Gesellschaft Hammer-Purgstall' in recognition of Joseph von Hammer-Purgstall's accomplishments.
He died in Vienna in 1856.