The Diocese of Ardagh and Clonmacnoise is a Roman Catholic diocese located in the central part of Ireland. It covers areas in counties Longford, Westmeath, and Roscommon. The diocese has a rich history, with its roots tracing back to early Christian times, particularly associated with the monastic site of Clonmacnoise, founded by Saint Ciarán in the 6th century. The diocese is part of the ecclesiastical province of Tuam and is governed by a bishop. The current bishop is responsible for overseeing the spiritual and administrative needs of the diocese, which includes various parishes and communities. The diocese plays a significant role in the religious life of the region.