The flag of Brittany (Breton: banniel Breiz; French: drapeau de la Bretagne), a region in the northwest of France, is called the Gwenn-ha-du ([ɡwɛnaˈdyː]), which means white and black, in Breton (French: blanc et noir).

The flag first came to the notice of a wider public at the Exposition Internationale des Arts Décoratifs et Industriels Modernes in Paris in 1925.

However its association with nationalist, fascist and separatist groups during the Second World War brought suspicions of collaboration to the flag.

Since then it has mostly lost an association with separatism in the mind of the public and become a widely accepted symbol for all Brittany and Bretons.

The older ermine field flag and black cross continue to be used, though rarely, by some individuals and groups.