Cöln was to have participated in a climactic sortie in the final days of the war, but a revolt in the fleet forced Admirals Reinhard Scheer and Franz von Hipper to cancel the operation.

In the first year after the start of World War I in July 1914, the German Kaiserliche Marine (Imperial Navy) suffered heavy losses among its light cruisers; by late 1915, the decision was made to begin construction on replacements.

The navy was no longer constrained by the naval laws that had previously governed expenditures, and war funding was allocated for the construction of ten new vessels.

Owing to the need to begin work as quickly as possible, only minor alterations were made to the preceding Königsberg class design, including the number of anti-aircraft guns and the location of the torpedo tubes.

[3] Cöln was to have carried three 8.8 cm SK L/45 anti-aircraft guns mounted on the centerline astern of the funnels, though only two were installed, due to shortages in artillery by that late point in the war.

[3][6] At that time, the unit also included her sister ship Dresden and the light cruisers Königsberg, Pillau, Graudenz, Nürnberg, and Karlsruhe.

During this period, on 19 June, Cöln and the rest of the unit sortied in an unsuccessful attempt to catch the aircraft carrier HMS Furious after she had struck the German seaplane base in the Tondern raid.

Cöln, Dresden, Pillau, and Königsberg were to attack merchant shipping in the Thames estuary while the rest of the Group were to bombard targets in Flanders, to draw out the British Grand Fleet.

[7] Scheer intended to inflict as much damage as possible on the British navy, in order to secure a better bargaining position for Germany, whatever the cost to the fleet.

"[9] On 9 November, two days before the armistice was to go into effect, British warships were reported to be in the area, and Cöln, Graudenz, and several torpedo boats were sent to intercept them, but they made no contact.

[6] Following the capitulation of Germany in November 1918, most of the High Seas Fleet's ships, under the command of Rear Admiral Ludwig von Reuter, were interned in the British naval base in Scapa Flow.

Reuter believed that the British intended to seize the German ships on 21 June 1919, which was the deadline for Germany to have signed the peace treaty.

On the morning of 21 June, the British fleet left Scapa Flow to conduct training maneuvers, and at 11:20 Reuter transmitted the order to his ships.

[14] In 2017, marine archaeologists from the Orkney Research Center for Archaeology conducted extensive surveys of Cöln and nine other wrecks in the area, including six other German and three British warships.