Seiz Breur was an artistic movement founded in 1923 in Brittany. Although it adopted the symbolic name seiz breur, meaning seven brothers in the Breton language, this did not refer to the number of members, but to the title of a folk-story. At its height it had fifty members united as the "Unvaniezh Seiz Breur" (Union of the Seven Brothers).
Though predominantly dedicated to the visual arts, the group also included writers, composers and architects. It is recognised today as an initiator of modern Celto-Breton art, but its memory has been marred by the association of several of its members with Nazi ideology and collaborationism.