William VI or
Guillem VI (died 1161) was the eldest son of
William V and his wife Ermessende, daughter of Count Peter II of Melgueil. William succeeded his father in the
lordship of Montpellier in 1121, while still a minor, under his mother's guardianship. He suppressed a revolt of the
bourgeoisie in 1143 and participated in several military campaigns of the
Reconquista in Spain (1134, 1146–47). He also increased the public character of the lordship in Montpellier and supported the growth of its trade.