Circa 1191, during the episcopate of John Comyn, Archbishop of Dublin, the original, wooden, Celtic St. Patrick's church on the site, which was outside the walls of Dublin, was raised to the status of cathedral. The present building, the largest church in Ireland, was built between 1200 and 1270, though a major rebuilding in the 1870s, necessitated by the belief that the cathedral was in imminent danger of collapse, means that much of the current building and decoration dates from the Victorian era. Though the rebuild ensured the survival of the Cathedral, a failure to preserve records of the scale of the rebuild means that little is known as to how much of the current building is genuinely mediæval and how much is victorian pastiche.
Throughout its long history the cathedral had contributed much to Irish life. The writer and satirist Jonathan Swift, author of Gulliver's Travels, was Dean of the cathedral from 1713 to 1745. His grave and epitaph can be seen in the cathedral.
From 1783 until 1871 the cathedral served as the Chapel of the Most Illustrious Order Saint Patrick, members of which were the Knights of St. Patrick. With the dis-establishment of the Church of Ireland in 1871 the installation ceremony moved to St. Patrick's Hall, Dublin Castle. The heraldic banners of the knights of those knights at the time of the move still hang over the choir stalls to this day.
Today the cathedral is the location for a number of public national ceremonials. Ireland's Remembrance Day ceremonies, hosted by the Royal British Legion and attended by the President of Ireland, take place there every November.
The funerals of two Irish presidents, Dr. Douglas Hyde and Erskine Hamilton Childers took place there, in 1949 and 1974 respectively. Because President Childers died in office, his state funeral was a major state occasion. The attendance included the King Baudouin of the Belgians, the Vice-President of the United States, Spiro T. Agnew (representing President Nixon), Earl Mountbatten of Burma (representing Queen Elizabeth II of the United Kingdom), British Prime Minister Harold Wilson and former prime minister Edward Heath.