The name Isabeau means God Is My Oath and is of French origin. Isabeau is a name that's been primarily used for girls.
Variation of the name Isabelle or a combination of the names Isabelle and Beau. Character in the movie Ladyhawke. Isabeau of Bavaria, House of Wittelsbach, was the eldest daughter of Duke Stephen III of Bavaria-Ingolstadt and Taddea Visconti of Milan. She became Queen of France when she married King Charles VI in 1385.