The Diocese of Ardagh is a Roman Catholic diocese located in the province of Connacht, Ireland. It covers parts of counties Longford, Westmeath, and Leitrim. The diocese has a rich history, dating back to the early Christian period, and is known for its significant contributions to the development of Christianity in Ireland. The diocese is part of the Archdiocese 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 numerous parishes and communities. The diocese also engages in various educational and charitable activities.