Marovo Lagoon is a large saltwater lagoon located in the New Georgia Islands, north of Vangunu Island, at 8°29′S 158°04′E / 8.48°S 158.07°E. It is part of the Solomon Islands. It encompasses 700 square km and is protected by a double barrier reef system.
The Marovo Lagoon World Heritage Area is located in the Marovo Lagoon. Sightings of Indo-Pacific Bottlenose Dolphin (Tursiops aduncus) have been confirmed in the lagoon.
There are many islands in the lagoon, some of which are inhabited. The people speak the Marovo language and live mainly by subsistence agriculture and are skilled at fishing. The lagoon is a popular destination for diving.