William II of Baux

William II des Baux (died 1239), a younger son of Prince William I of Orange, became co-prince of Orange with his elder half-brother Raymond I after their father was killed by the Albigensians in 1218, and he founded the Baux-Orange line.

In alliance with the citizens of Marseille and his cousins, he warred against Count Raymond Berengar IV of Provence, and in 1233 joined the peace treaty ending the Provençal civil war. He died in 1239, leaving sons who included the later co-princes William III and Raymond II.