Groix (French: Île de Groix, Breton: Enez Groe) is an island and a commune in the Morbihan department of the region of Brittany in north-western France.
Groix lies a few kilometres of the coast off Lorient. Several ferries a day run from Lorient to Groix.
There are a few small towns on the island. High cliffs are on its north coast and sandy beaches in secluded coves on the south coast. Groix is also home to a wide variety of sea birds.
The geology of Groix is distinct from that of the nearby continent, and the east and south coasts have been designated a mineral nature reserve since 1982. More than 60 minerals can be found on the island, particularly blue glaucophane (observable on the surface), epidote or garnet. The island mainly consists of schist.
Groix provides a dramatic backdrop for the fourth novel of Peter May's "Enzo" series, Freeze Frame, published in 2010.