The Bishop of Cashel and Ossory (Full title: Bishop of Cashel, Waterford and Lismore with Ossory, Ferns and Leighlin) is the Ordinary of the United Diocese of Cashel, Waterford and Lismore with Ossory, Ferns and Leighlin in the Church of Ireland. The diocese is in the ecclesiastical province of Dublin.
When the Church in England broke communion with the Roman Catholic Church, the Church of England was established by the state as the established church. Later, by decree of the Irish Parliament, a similar new body became the State Church in the Kingdom of Ireland. It assumed possession of most Church property (and so retained a great repository of religious architecture and other items, though some were later destroyed). The substantial majority of the population remained faithful to the Latin liturgy of Roman Catholicism, despite the political and economic advantages of membership in the state church. The English-speaking minority mostly adhered to the Church of Ireland or to Presbyterianism. In 1833, the two provinces of Dublin and Cashel were merged. Over the centuries, numerous dioceses were merged, in view of declining membership. The same is true for this diocese where it can be seen that each of the entities listed in the title would have been a diocese in its own right. It is for this reason that the united diocese has six cathedrals.