Archduke Friedrich, Duke of Teschen (Friedrich Maria Albrecht Wilhelm Karl; 4 June 1856 – 30 December 1936) was a member of the House of Habsburg-Lorraine and the Supreme Commander of the Imperial and Royal Armed Forces of the Austro-Hungarian Empire during World War I, having previously served as both commander-in-chief of the Imperial-Royal Landwehr and inspector-general of the Austro-Hungarian Army.

Friedrich owned properties at Ungarisch-Altenburg (now Mosonmagyaróvár in Hungary), Belleje, Saybusch (now Żywiec in Poland), Seelowitz (now Židlochovice) and Frýdek in the Czech Republic, and Pressburg (now Bratislava in Slovakia).

[1] In World War I, he was —from the dynastic point of view —as grandson of the victor of the Battle of Aspern-Essling, Archduke Charles, and as nephew of the victor of the Battle of Custoza, Archduke Albrecht, the predestined head of the armed forces of Austria-Hungary; and on 11 July 1914 Friedrich was appointed supreme commander of the Austro-Hungarian Army by Emperor Franz Joseph I.

He thought it his duty to accept this heavy responsibility, but, modestly underestimating his own powers, left the actual exercise of the command to his chief of staff, Franz Conrad von Hötzendorf.

The funeral and burial in the parish church in Mosonmagyaróvár was attended by his nephew, the exiled King of Spain; by numerous archdukes; by all the surviving Austro-Hungarian field marshals; by personal representatives of Hitler; by members of the House of Savoy; by the diplomatic corps; by a son of exiled German Kaiser Wilhelm; by representatives of the governments of Germany, Italy and Austria, and by Hungary's regent, Miklós Horthy and his wife.