The official symbol or coat of arms of Ireland is the harp and has been since medieval times. The current design is based on the 'Brian Boru harp' of the 14th Century, which can be found in the museum of Trinity Colleges in the heart of Dublin.

The Harp is engraved on the official seal of the President of Ireland. The President's flag consists of a golden harp (or) with silver strings (argent) on blue (azure).

The harp is used by the Government, its agencies and representatives in Ireland and abroad. The harp is also featured on the reverse side of all Irish Euro coins.

The 'Shamrock', a member of the clover family, is an unofficial symbol of Ireland. According to tradition St. Patrick used a shamrock to explain the Holy Trinity to the pagan kings of ancient Ireland. By showing that one leaf of shamrock had three parts he was able to explain that the Christian God had three aspects to His being; God the Father; God the Son; and God the Holy Spirit (the Holy Trinity).

People wear a sprig of shamrock on 17th March, St. Patrick's Day, the National Day of Ireland.