The Île de Batz (French pronunciation: [il də ba]; Breton: Enez-Vaz) is an island off Roscoff in Brittany, France.

Administratively, it is a commune in the Finistère department of Brittany in north-western France.

The average annual rainfall is 894.4 mm (35.21 in) with December as the wettest month.

The temperatures are highest on average in August, at around 17.0 °C (62.6 °F), and lowest in February, at around 7.7 °C (45.9 °F).

Inhabitants of Île-de-Batz are called in French Batziens or Îliens.