Arnaud Amanieu (also Arnold and Amaneus, 4 August 1338–1401) was the Lord of Albret from 1358.
Amanieu held lands in Gascony which by the Treaty of Brétigny (1360) were obtained by Edward III of England. Edward III appointed his son Edward, the Black Prince Prince of Aquitaine and Gascony, and in 1363 Amanieu paid homage to the two Edwards. In 1368 Amanieu in a secret treaty switched his allegiance to Charles V of France.