Reply To: What is the tallest church spire in Ireland? Home › Forums › Ireland › What is the tallest church spire in Ireland? › Reply To: What is the tallest church spire in Ireland? July 8, 2002 at 12:59 pm #720118 Michael J. OBrienParticipant I believe it is St Johns RC Cathedral in Limerick. It is 280ft high or 85 metres. This is usually quoted in tourist leaflets for Limerick. Don’t know about the Cathedral in Monaghan. Latest News