Erdeven (French pronunciation: [ɛʁdəvɛn]; Breton: An Ardeven) is a commune in the Morbihan department in the region of Brittany in north-western France.

Its main industry is tourism. Attractions include a seven kilometre-long beach beside the Atlantic and many prehistoric sites featuring megaliths. The Mané-Croch, Mané-Bras and Crucuno dolmens and the Kerzérho alignments lie just outside the commune.

Inhabitants of Erdeven are called Erdevenois in French.

It is twinned with St. Märgen in the Black Forest region of Germany.