Like Reunion, Rodrigues and the reefs of Saint-Brandon, Mauritius is part of the Mascarene archipelago. It is located 2,000 km off the southeast coast of Africa, 865 km east-southeast of the eastern coast of Madagascar and 199 km east-northeast of Saint-Denis (Reunion). Between latitudes 19° 58.8' and 20° 31.7' S and longitudes 57° 18.0' and 57° 46.5' E, it is an island 65 km long by 45 km wide. wide, for an area of ​​1,864.8 km22.3.

The island is surrounded by more than 150 km of white sand beaches, lined with coconut and casuarina trees. The elevation rises from the coastal plains to a central plateau where it reaches 670 m. The plains and the plateau allowed the extensive cultivation of sugar cane and tea. The island includes a broken ring of small mountains (300–800 m), with the highest point being the Piton de la Petite Rivière Noire (828 m), in the Rivière Noire Gorges National Park. Streams and rivers dot the island, many of which fit into faults in or between the lava flows.

The lagoons are protected from the open sea by the third largest coral reef in the world, which surrounds the island. Off the coast of Mauritius lie some 49 uninhabited islands and islets, several of which have been declared nature reserves for threatened species.