Cathedral of the Most Holy Trinity, Waterford

The Cathedral of the Most Holy Trinity serves as the cathedral church of the Roman Catholic Diocese of Waterford and Lismore. Notably, it is the oldest post-Reformation Catholic cathedral in Ireland, predating the Roman Catholic Relief Act of 1829 by 36 years. The site had previously been occupied by a chapel known locally as the 'Big Chapel,' built in 1693.

The cathedral was designed by the esteemed architect John Roberts in 1793, following the earlier Roman Catholic Relief Act of the same year. Roberts, a prominent figure in Waterford's architectural history, also designed the nearby Christ Church Cathedral, the Church of Ireland cathedral in the city. The construction of the cathedral was overseen by Rev. Dean Thomas Hearn, D.D., who played a crucial role in its development. Roberts was reportedly deeply involved in the building process, visiting the site daily and ultimately succumbing to an illness contracted within the unfinished structure.

A significant feature of the Cathedral of the Most Holy Trinity is its pipe organ, crafted in 1858 by the renowned London firm William Hill & Sons. This organ is the third to be installed in the cathedral, with the first originating from the 'Big Chapel' in 1773 and later transferred to the new building. The second organ, a one-manual instrument, was built in 1826 by Calvin and William Porter Draper, who operated a workshop in Manor Street.