The Lord Bishop of Leighlin was a separate episcopal title which took its name after the small town of Old Leighlin in County Carlow, Ireland.
The title is now united with other bishoprics. In the Church of Ireland, it is held by the Lord Bishop of Cashel and Ossory, whose full title is the Lord Bishop of Cashel, Waterford, Lismore, Ossory, Ferns and Leighlin. In the Catholic Church, it is held by the Lord Bishop of Kildare and Leighlin.