[2] 94.7 ha (234 acres) in size, it is located 3.8 km ESE of Félicité Island.

The tallest peak on the island is Estel Hill, at 130 meters.

Presently, Marianne Island is uninhabited but is routinely visited by tourists and boaters.

There was a former settlement called La Cour, and in 1940 the island had 60 inhabitants.

Reportedly, the rare Seychelles paradise flycatcher (Terpsiphone corvina) is occasionally spotted on the island.