Lastovo, also known as Lagosta, is an archipelago municipality located in the Dubrovnik-Neretva County of Croatia. The municipality encompasses a total land area of approximately 53 square kilometres (20 sq mi) and consists of 46 islands.
The largest island within the archipelago shares the name Lastovo and serves as the primary residential hub, containing 46 square kilometres (18 sq mi) of its own land area. The majority of the municipality's population lives on this main island. The total population of the archipelago is 792 people, of whom 94.7% are ethnic Croats.