The Fort du Portalet is a fort in the Aspe valley in Bearn, French Pyrenees.
The present-day fort was begun in 1842 and finished in 1870, replacing earlier structure a little way north. The fort guards access to the Col du Somport. During WWII, the fort was occupied by the Germans and used as a prison. Its military use ceased in 1945. Abandoned, it was bought by the local authorities in 1999 who are in the process of restoring it.
From 15 August to 16 November 1945 Philippe Pétain, the President of the Vichy Regime was imprisoned here after his trial. Later he was moved to the Forte de Pierre citadel on the Île d'Yeu where he died.