The Diocese of Meath (Irish: Deoise na Mí) is an Irish diocese which took its name after the ancient Kingdom of Meath. In the Roman Catholic Church it still exists as a separate diocese, but in the Church of Ireland it has been united with other dioceses.
Clonard Abbey was founded by Saint Finnian, first Abbot of Clonard, in the early sixth century. There had been a number monastic bishops at the abbey, but it was not until the Synod of Rathbreasail in 1111 that the diocese of Clonard was established. Its boundaries were set at the Synod of Kells in 1152, which covered roughly the western part of the Kingdom of Meath with the diocesan bishop's seat (cathedra) located at Clonard Abbey. During the twelfth century the bishops of Clonard acquired most of Meath as their territory, and frequently used the title "bishop of Meath" or "bishop of the men of Meath". After Bishop Simon Rochfort transferred his seat from Clonard to Trim in 1202, the title "bishop of Meath" became the normal style.
In the Church of Ireland, the diocese of Meath united with Clonmacnoise in 1569, although only the single name of Meath to be continued. In 1976, the diocese of Meath was transferred from the Province of Armagh to Dublin. At the same time the diocese of Kildare was separated from Dublin and Glendalough and the new Diocese of Meath and Kildare was formed. The bishop has two seats: Trim Cathedral and Kildare Cathedral. The current Church of Ireland bishop is the Right Reverend Pat Storey, Bishop of Meath and Kildare, who was elected in 2013.
In the Roman Catholic Church, Meath is still a separate diocese. The Roman Catholic bishop's seat is located at Christ the King Cathedral, Mullingar. The current bishop is the Most Reverend Michael Smith, Bishop of the Roman Catholic Diocese of Meath, who succeeded to the title on 16 May 1990.