The island gives its name to the archipelago of the so-called Curzolane, that is to say the group of southern Dalmatian islands formed by Korcula itself, Mljet and the archipelago of Lastovo.

Like many neighboring islands, Korcula has an elongated shape in an east-west direction and measures 46 km in length from Cape Terstena, in the southwest, to the extreme eastern point of Cape Speo, maximum of 7.8 km in width. The island is bathed in the north by the Curzola channel, which separates it from the island of Lesina, in the east by the Peljesac channel, which separates it from the mainland, in the south by the Lastovo channel, which overlooks the island of the same name, and west from the Adriatic Sea.