According to the Irish Seismic Network:"The largest recorded earthquake to have occurred in Ireland was a magnitude 2.3ML in Co. Leitrim in November 1994. There were no felt reports for this event.
"The largest recorded earthquake we have had offshore Ireland was a magnitude 5.4ML near the Welsh coast on 19 July 1984. This was felt mainly in Wales and adjacent parts of Britain, and over a significant area of the east coast of Ireland. There was some structural damage reported from North Wales adjacent to the epicentre of the event. More significant damage would have resulted had the event occurred at less than the estimated 20km depth."
Sounds pretty safe, earthquake-wise!
Happy St. Patrick's Day!