The Roman Catholic Diocese of Kilmore is a diocese located in the province of Ulster, Ireland. Established in the 12th century, it serves the spiritual needs of the Catholic community in the region. The diocese is part of the Catholic Church and is governed by a bishop, currently Bishop Martin Hayes. The diocese encompasses several counties, including Cavan and parts of Leitrim and Monaghan. Its main church is the Cathedral of St. Patrick and St. Felim in Cavan Town. The diocese is involved in various educational and social initiatives, promoting the teachings of the Catholic faith.