St. Mary’s is the Roman Catholic cathedral for the Diocese of Ossory. It is situated on James’s Street, Kilkenny, County Kilkenny, Ireland. Kilkenny also has a second cathedral, Saint Canice’s which is Church of Ireland.

Saint Mary’s was designed by William Deane Butler (c.1794-1857). He was chosen by Bishop William Kinsella (1793-1845) who instigated the building of St. Mary’s in February 1842. Work began in April 1843 and finished in 1857, it is worth noting that this included the period of the Irish famine. On Sunday the 4th October 1857, St. Mary’s had its grand opening, which consisted of a two and three quarter hour ceremony that began at 6.15am. The cost of the building is estimated to have been £25,000.

St. Mary’s is made from cut-limestone which was sourced locally. The cathedral has a cruciform plan and its style is described as ‘Early English Gothic’[1]. The design is believed to have been based on Gloucester Cathedral in Gloucester, England. It is situated on the highest point in Kilkenny City and is a significant local landmark.

The cathedral actually has three names - St Mary’s, the church of St Kieran and the Cathedral of the Assumption.

St. Mary's has a noted sculpture of the Madonna by Giovanni Maria Benzoni (1809-1873).