The Operational Zone of the Adriatic Littoral was a Nazi German district on the northern Adriatic coast created during World War II in 1943. It was formed out of territories that were previously under Fascist Italian control until its takeover by Germany. It included parts of present-day Italian, Slovenian, and Croatian territories. The area was administered as territory attached, but not incorporated, to the Reichsgau of Carinthia. The capital of the zone was the city of Trieste.

Trieste is a city and seaport in northeastern Italy. It is the capital and largest city of the autonomous region of Friuli-Venezia Giulia, as well as of the regional decentralization entity of Trieste.