The island, with its neighbouring islets, forms the commune of Île-de-Sein in the Finistère department of Brittany in north-western France.

[3] The island women used to wear a black headdress, and in the past, they had a reputation for enticing sailors onto the rocks by witchcraft.

After hearing General de Gaulle's call to resistance during World War II in his appeal to the French on 18 June 1940, every male inhabitant aged between 14 and 54[citation needed] (or 60, according to the island's official website[5]) (variously totalled as 114 to 128[citation needed]) set sail in their fishing boats for Britain to join the Free French forces.

During the 1960s, French artists Maurice Boitel and Jean Rigaud painted on the Île de Sein.

According to Breton legend, Île de Sein was once home to a group of virgin druid priestesses called the Gallizenae.