The Abbey of Saint Gall is a dissolved abbey (747–1805) in a Catholic religious complex in the city of St. Gallen in Switzerland. The Carolingian-era monastery existed from 719, founded by Saint Othmar on the spot where Saint Gall had erected his hermitage. It became an independent principality between 9th and 13th centuries, and was for many centuries one of the chief Benedictine abbeys in Europe. The library of the Abbey is one of the oldest monastic libraries in the world.

An abbey is a type of monastery used by members of a religious order under the governance of an abbot or abbess. Abbeys provide a complex of buildings and land for religious activities, work, and housing of Christian monks and nuns.