Operation Rheinübung was the last sortie into the Atlantic by the new German battleship Bismarck and heavy cruiser Prinz Eugen on 18–27 May 1941, during World War II. This operation aimed to block Allied shipping to the United Kingdom as the previously successful Operation Berlin had done. After Bismarck had sunk HMS Hood during battle of the Denmark Strait, it culminated with the sinking of Bismarck, while Prinz Eugen escaped to port in occupied France. From that point on, Germans would rely only on U-boats to wage the Battle of the Atlantic.

Bismarck was the first of two Bismarck-class battleships built for Nazi Germany's Kriegsmarine. Named after Chancellor Otto von Bismarck, the ship was laid down at the Blohm & Voss shipyard in Hamburg in July 1936 and launched in February 1939. Work was completed in August 1940, when she was commissioned into the German fleet. Bismarck and her sister ship Tirpitz were the largest battleships ever built by Germany, and two of the largest built by any European power.