William VIII (in Occitan: Guilhem; died 1202) was Lord of Montpellier, the son of William VII and Matilda of Burgundy.
William VIII married Eudokia Komnene, grand-niece of the Byzantine emperor Manuel I Komnenos. They had one daughter, Marie of Montpellier.
Lacking a male heir, William separated from Eudokia, sending her to a monastery in Ariane.<br> William then married Agnes of Castile and sired eight more children:
The Pope ruled William's marriage to Agnes as illegitimate and Marie was given the throne.
William VIII was a patron of troubadours. Arnaut de Mareuil came to his court after fleeing from the entourage of Azalais of Toulouse, and at least one of Arnaut's poems is addressed to him.