OSSORY, DIOCESE OF. - Diocese in Ireland, in the province of Leinster, suffragan of the diocese of Dublin. It has an area of 2400 sq. km. with a population of 76,038 inhabitants, of whom 73,234 are Catholics; it comprises 41 parishes served by 130 diocesan priests and 47 regular clergy; 6 male and 26 female religious communities (Ann. Pont., 1952, p. 304).
In 1118, at the Synod of Rathbreasail, the boundaries of the diocese were fixed. After the 12th century, the see of the diocese was Kilkenny; there, in 1317, Richard Ledrede, a Franciscan, held a synod for the diocesan clergy. During the Reformation, the people of Ossory remained faithful to Catholicism and drove out John Bale, whom Edward VI of England nevertheless attempted to impose upon them as bishop. In the years 1602-18 and 1650-69 Ossory was without a bishop, but between 1618 and 1650 it was governed by David Rothe, one of the most renowned bishops in the history of the diocese. In 1621 he was the only bishop in Ireland and played a very notable part in the formation of the Catholic Confederation at Kilkenny in 1642. Other bishops worthy of mention subsequently were the Dominicans Thomas de Burgo (1759-76) and J. Th. Troy (1776-86). In 1838 a diocesan college was opened at Ossory.
Among the religious monuments may be mentioned the cathedral of St. Mary, begun in 1843 and completed in 1857. The patron saint of the diocese is St. Kieran, who lived about the year 500 and whose feast is celebrated on March 5; until 1773 this feast was observed in the diocese as a holy day of obligation.