Louis, Duke of Brittany, or variations on this name, may refer to:
Louis XII of France (1462-1515), who by marriage to Duchess Anne of Brittany, was Duke of Brittany Louis, Duke of Brittany (born 1704), died in 1705, eldest son of Louis, Duke of Burgundy (Dauphin of France) and Princess Marie Adélaïde of Savoy Louis, Duke of Brittany (born 1707), died in 1712, second son of Louis, Duke of Burgundy and Princess Marie Adélaïde of Savoy, briefly succeeded his father as Dauphin