William IX.
William IX. is the name of the following people:
- William IX. (Aquitaine) , the Trobador , Duke (1086–1127)
- William IX. (Auvergne) , Count (1194–1195)
- William IX. of Hessen-Kassel , see Wilhelm I. (Hessen-Kassel)
William IX. is the name of the following people: