Clare Abbey is a ruined Augustinian monastery placed close to Ennis, along the banks of the Fergus River, and approximately a mile north of Clarecastle in County Clare, Ireland. The abbey was founded in 1195 under the sponsorship of Domnall Mor Ua Briain Donald O'Brien, the king of Thomond. It turned into the primary and biggest of the Augustinian monasteries in County Clare. After the dissolution of the monasteries in 1543 the parish lands, now the civil parish of Clareabbey, had been given to the Barons of Ibrackan via King Henry VIII of England. In 1620 it became the assets of the Earl of Thomond.
The ruins encompass a church and cloister with levels of domestic buildings to the east and south of the garth, and a gateway and enclosures. The church become at the beginning an extended oblong building, 39 metres by 9 metres 40 centimetres, externally. The interior became ultimately divided right into a nave and chancel with the aid of a belfry tower 4 metres 80 centimetres, and the chancel 14 metres 75 centimetres.