Îlet Duquesnay is an islet of the peninsula of St. Anne. It is administratively integrated into the municipality of Marin. It is a volcanic islet. With Îlet Petit-Dupre is the only islet of the town of Marin.
The islet owes its name to Osman Duquesnay, former mayor of the commune who was born in the commune and lived there all his life. He was also deputy of Martinique from 1898 to 1902 and from 1906 to 1910.
It is currently a private property of the State.
It is uninhabited and inaccessible to visitors. It is not possible to visit it, but it can be seen by going to Sainte-Anne or from the beach of Club Med.
Îlet Duquesnay is the object of a particular attention of the services of environmental protection.