Belle-Île ou Belle-Île-en-Mer is a French island off the coast of Brittany in the département of Morbihan, and the largest of Brittany's islands. It is 14 km from the Quiberon peninsula. It is also the seoncd biggest island in France after Corsica.
The island measures 17 km by 9 km and has an average altitude of 40 m. The area is about 84 km2. The coasts are a mixture between dangerously sharp cliff edges on the southwest side, the Côte Sauvage (Wild coast), and placid beaches, the largest being les Grands Sables (The great sands) and navigable harbours on the northeast side.
The two main ports are Le Palais (accessible by ferry from Quiberon, Port-Navalo and Vannes) and Sauzon (accessible by ferry from Quiberon and Lorient).