Saint-Maurice d'Agaune (or Saint-Maurice-en-Valais) is a Swiss monastery of canons regular in Saint-Maurice, Canton of Valais, which dates from the 6th century. It is situated against a cliff in a section of the road between Geneva and the Simplon Pass (to northern Italy). The abbey itself is a territorial abbacy and not part of any diocese. It is best known for its connection to the story of the martyrdom of the Theban Legion, its original practice of perpetual psalmody, and a renowned collection of art and antiquity.