Amaury III de Montfort (d.18 or 19 April 1137) was a French nobleman, the Seigneur of Montfort-l'Amaury, Épernon, and Houdan in the Île-de-France (1101–c.
Amaury was the son of Simon I, seigneur de Montfort, and his wife Agnès d'Évreux, daughter of Richard, Count of Évreux.
[5] When his maternal uncle William, Count of Évreux died in 1118, he left no direct heirs so Henry I of England seized his lands.
[7] His sister was the notorious Bertrade de Montfort, his nephew was Fulk V of Anjou, and his kinsman King Louis VI of France was related to him by marriage.
[7] Amaury had induced his nephew Fulk V to attack Henry's territories in the past[8] while the French and English kings were at odds again.