St. Mary's Cathedral, Killarney is a Roman Catholic cathedral in County Kerry, Republic of Ireland. St. Mary's Cathedral (1842-1855) was designed by the renowned English Architect Augustus Welby Pugin and is considered to be one of the most important and best Gothic Revival churches of the 19th. century in Ireland. The Spire and nave were completed by the Irish Architects Ashlin and Coleman of Dublin. The interior decorations were designed by J.J. McCarthy.
Some people believe that the nave is too narrow, but they are wrong, the width of the nave was based on the medieval models to be found throughout Ireland and England. The spire is very tall and elegant. The west end is very Irish in character with three tall lancet windows and a very low entrance door beneath. The stonework used is most attractive mixture of brown and grey stone. The siting of the church is more like the siting of a priory that the siting of a cathedral because the cathedral stands in a huge field instead of sitting in an urban setting.