Les Frères Morvan, also known as Ar Vreudeur Morvan in Breton, were a French musical group from Saint-Nicodème, Côtes-d'Armor. Formed in 1958 by four brothers—Yves, François, Henri, and Yvon—they began their career as traditional singers, performing at local festivals and events. Their breakthrough came with the rise of fest-noz (Breton dance parties) in the late 1950s, leading to frequent performances across Brittany. The group released several albums, including Ar vreudeur Morvan (1974), Fest-noz à Botcôl (1999), and Un demi-siècle de Kan ha Diskan (2009). Known for their traditional Breton songs and kan ha diskan (call-and-response) style, they performed over 3,000 times. The group received numerous distinctions for promoting Breton culture, including the Knights of Arts and Letters in 2002. All members have since passed away: Yves in 1984, François in 2012, Yvon in 2022, and Henri in 2025.