There is no sea between Italy and Serbia because they do not share a maritime boundary. However, the Adriatic Sea—a northern arm of the Mediterranean—lies between Italy's eastern coast and the Balkan Peninsula, where Serbia is located inland.
Semi-enclosed sea (800 km long, 200 km wide), connecting to the Ionian Sea via the Strait of Otranto. Key ports: Venice, Trieste, Rijeka, Split, Dubrovnik, Bar, Durrës. Vital for trade, tourism, fisheries, and naval access.
So while Italy and Serbia are separated by the Adriatic region, Serbia itself has no sea access—it's a landlocked nation whose nearest seaport is via Croatia or Montenegro.