James Joseph McCarthy was an Irish architect famous for his design of ecclesiastical buildings. McCarthy was born in Dublin, Ireland on the 6th of January 1817. His parents were from County Kerry. He was educated by the Christian Brothers in Richmond St., and went on to study architecture at the Royal Dublin Society School. He was a follower of the style of the architect Pugin and Gothic Revival.
McCarthy served as Professor of Ecclesiastical Architecture at All Hallows College, Dublin. He was also appointed Professor of Architecture at the Catholic University of Ireland and at the Royal Hibernian Academy. McCarthy was a friend of Dr. Bartholomew Woodlock, who had been rector of both All Hallows' and the Catholic University, and he helped Woodlock to found the Irish Ecclesiological Society in 1849. He was also a close friend of Charles Gavan Duffy and was a member of the Young Irelanders.
He died in 1882 and is buried in Glasnevin Cemetery.
J.J McCarthy completed over fifty commissions for Churches, Monasteries, Convents and Cathedrals.