Since the Reformation the mother church of the Protestant archdiocese of Cashel had been St. Patrick's Cathedral, gloriously situated on the Rock of Cashel. That cathedral, built in the thirteenth century, had gradually fallen into disrepair, and was closed for worship in 1721. With the medieval parish church serving as the de-facto cathedral in the meantime, construction on a new cathedral was completed in 1784. Cashel was one of two Irish cathedrals built in the eighteenth-century Georgian style, the other being at Waterford.
The spire was not part of the original cathedral, but was later added in 1812.The cathedral is classically Georgian in its form and appearance, with aedicules, pediments, pilasters, rounded windows and a spire. Alongside the cathedral was built a library, also designed in the Classical style, dedicated to Theophilus Bolton (1678-1744), archbishop of Cashel.
View towards the chancel.
The chancel was remodeled in the nineteenth century in a gilded Italianate style by local architect, William Atkins.