St Aidan's Cathedral, Enniscorthy, County Wexford, is a monumental cathedral. It is the largest building in Ireland constructed to designs prepared by Augustus Welby Northmore Pugin (1812-1852), reputedly based on Tintern Abbey in Wales. Due to fears of potential collapse, the tower and spire were rebuilt under the supervision of JJ McCarthy (1817-1882) but retained the Pugin defined profile.

Constructed in dressed local stone, including stone from the nearby ruined Franciscan friary salvaged 1843-1847, with carved granite accents, it has quite an austere exterior. The interior contains stained glass panels by Lobin of Tours, Mayer of Munich, and Earley of Dublin, a pipe organ supplied by White and Son, Dublin, an altar signed by James Pearse (1839-1900) and Edmund Sharpe (1853-1930) of Dublin.

St Aidan's Cathedral has been dramatically refurbished in recent years to the original plans of distinguished architect, Augustus Welby Pugin. Enniscorthy's Cathedral is named after the patron saint of the Diocese of Ferns and is the religious centre for all major Roman Catholic ecclesiastical ceremonies.