The Croatian Naval Legion (Croatian: Hrvatska pomorska legija) was a contingent of volunteers from the Independent State of Croatia that served with Nazi Germany's navy Kriegsmarine, on the Black Sea and Adriatic Sea during World War II.

[3] The Croats purpose in posting a naval contingent to the Black Sea was to evade the prohibition on an Adriatic navy imposed by the Treaty of Rome (18 May 1941) with Italy.

[4] It managed to scrounge up 47 damaged or abandoned fishing vessels, mostly sailing ships, and to man them with hired local Russian and Ukrainian sailors, many of them deserters from the Soviet Red Navy.

On 24 September 1942, the Poglavnik Ante Pavelić visited the naval headquarters, where he reached an agreement with German authorities to train and equip a submarine chaser flotilla[6] the Legion became Unterseebootsjäger-Flotille 23.

[5] In 1943, the legion was expanded with a Croatian volunteer coastal artillery unit,[2] bringing the total manpower to more than 1,000 men.