Dysert (Irish: An Díseart, meaning 'hermitage') is a civil parish in County Clare, Ireland. The parish was formerly called Dysert O’Dea, from its having been the territory of the sept of that name. It is part of the ecclesiastical parish of Dysart and Ruan. The ruins of O'Dea Castle and a 12th-century church of Dysert O'Dea Monastery are in the townland of the same name.