Karlsruhe was a light cruiser, the second member of the Königsberg class, and was operated between 1929 and April 1940, including service in World War II. She was operated by two German navies, the Reichsmarine and the Kriegsmarine. She had two sister ships, Königsberg and Köln. Karlsruhe was built by the Deutsche Werke shipyard in Kiel; she was laid down in July 1926, launched in August 1927, and commissioned into the Reichsmarine in November 1929. She was armed with a main battery of nine 15 cm SK C/25 guns in three triple turrets and had a top speed of 32 knots (59 km/h; 37 mph).

Like her sisters, Karlsruhe served as a training cruiser for naval cadets throughout the 1930s. During the Spanish Civil War, she joined the non-intervention patrols off the Spanish coast. She was in the process of being modernized at the outbreak of World War II in September 1939, and so she was not ready for action until April 1940, when she participated in Operation Weserübung, the invasion of Norway. She landed troops at Kristiansand, and while returning to Germany, she was attacked by the British submarine HMS Truant; two torpedoes hit the ship and caused significant damage. Unable to return to port, Karlsruhe was scuttled by one of the escorting torpedo boats.