OLERON, an island situated on the coast of France, in the department of the Lower Charente. It is about ninety square miles in extent, and is opposite the mouths of the rivers Charente and Seudre. It is separated from the mainland by the strait called the Pertuis de Maubuisson. Oleron is a fertile spot, especially on the east and south parts, and yields good corn, wine, and brandy. There are also extensive marshes, from which salt is collected. It contains about 15,000 inhabitants, who are expert seamen and fishermen.