Corisco, Mandj, or Mandyi,[1] is a small island of Equatorial Guinea, located 29 km (18 mi) southwest of the Río Muni estuary that defines the border with Gabon.

Corisco, whose name derives from the Portuguese word for lightning, has an area of 14 km2 (5 sq mi), and its highest point is 35 m (115 ft) above sea level.

The most important evidence of human occupation comes from the area of Nandá, near the eastern coast, where dozens of prehistoric burials have been excavated.

During the second period, tombs have been documented where the corpses (not preserved) lay surrounded by pots, probably containing food and alcoholic beverages.

In February 2003, Gabonese Defence Minister Ali-Ben Bongo Ondimba visited the islands and re-stated Gabon's claim to them.