SM U-36 (Austria-Hungary)

SM U-36 was a German-built U-boat that served in the Austro-Hungarian Navy (K.u.K. Kriegsmarine) during World War I. Originally designated as U-21 in German service, she was ceded to Austria-Hungary in March 1917 as part of an agreement to bolster the Dual Monarchy's U-boat fleet.

Commissioned into the Austro-Hungarian Navy as SM U-36 ( SM standing for Seiner Majestät or "His Majesty's"), she was primarily deployed in the Adriatic Sea, operating against Italian, French, and British shipping. She was equipped with torpedoes and deck guns for engaging enemy vessels.

U-36 was successful in sinking several ships during her service. One notable sinking was the Italian auxiliary cruiser Minerva in 1917.

The operational history of U-36 ended after the war. Following the armistice in November 1918, the submarine was surrendered to the Allies. She was subsequently ceded to Italy as a war reparation. In 1920, she was scrapped in Italy.