The Benedictine Pannonhalma Archabbey or Territorial Abbey of Saint Martin on Mount Pannonhalma is a medieval building in Pannonhalma and is one of the oldest historical monuments in Hungary. Founded in 996, it is located near the town, on top of a hill. Saint Martin of Tours is believed to have been born at the foot of this hill, hence its former name, Mount of Saint Martin, from which the monastery occasionally took the alternative name of Márton-hegyi Apátság. This is the second largest territorial abbey in the world, after the one in Monte Cassino.

Pannonhalma is a town in Győr-Moson-Sopron County, western Hungary, with approximately 4,000 inhabitants. It is about 20 km (12 mi) from Győr. Archduke Otto Habsburg's heart is kept at the Pannonhalma Archabbey, while his body was laid at the Capuchin Crypt in the old Imperial capital of Vienna.