William of Blois

William of Blois or William de Blois may refer to:

• William, Count of Blois (c.772–834), count of Blois from 830–34
• William, Count of Sully (c.1085–c.1150), count of Blois from 1102–07, brother of King Stephen of England
• William I, Count of Boulogne (c.1137–1159), count of Boulogne from 1153–59, son of King Stephen of England
• William of Blois (poet) (fl.1167), abbot of Maniaci, sometimes confused with the bishop of Lincoln
• William de Blois (bishop of Lincoln), in office from 1203–06, probably related to the bishop of Worcester
• William de Blois (bishop of Worcester), in office from 1218–36, probably related to the bishop of Lincoln