Red Abbey, Medieval ruins of Augustinian friary in Cork City Centre, Ireland

Red Abbey is the surviving bell tower of a 13th- or 14th-century Augustinian friary, built from the reddish sandstone that gave the site its name. The square tower, the crossing tower of the abbey church, stands in the area of Dunbar and Margaret Street and is the only visible medieval structure left in Cork.

The Red Abbey was founded by a member of the De Courcey family between 1270 and 1288, on land granted by Norman town lords, and was dedicated to the Holy Trinity. Augustinian friars lived there until at least the 1641 rebellion, possibly as late as 1700. The tower served John Churchill as a battery during the 1690 Siege of Cork. After 1717 the buildings became a sugar refinery, and a fire on 7 December 1799 destroyed most of the abbey, leaving only the church tower.

The name Red Abbey comes from the reddish sandstone used to build the Augustinian church, whose dedication was to the Holy Trinity. The friary stood off Dunbar and Margaret Street, and the tower is the only medieval structure still visible in Cork. William Tirry (1609–1654), a friar of this Augustinian house, was executed after the Cromwellian conquest and beatified in 1992.

The ruins are located near Douglas Street and Nano Nagle Place with free public access to view the exterior. You can walk around the tower to examine the Gothic details and structural features from multiple angles.

Archaeological excavations in 1977 uncovered medieval pottery and over 300 pieces of lead shot scattered across the grounds. These findings reveal details about daily life at the site and suggest past violence during its occupation.