The Grand Lodge of Ireland is the second most senior Grand Lodge of Freemasons in the world, and the oldest in continuous existence. Since no specific record of its foundation exists, 1725 is the year celebrated in Grand Lodge anniversaries, as the oldest reference to Grand Lodge of Ireland comes from the Dublin Weekly Journal of 26 June 1725. This describes a meeting of the Grand Lodge to install the new Grand Master, The 1st Earl of Rosse, on 24 June. The Grand Lodge has regular Masonic jurisdiction over 13 Provincial Grand Lodges covering all the Freemasons of the island of Ireland, and another 11 provinces worldwide.

Freemasonry or Masonry refers to fraternal organisations that trace their origins to the local guilds of stonemasons that, from the end of the 14th century, regulated the qualifications of stonemasons and their interaction with authorities and clients. Modern Freemasonry broadly consists of two main recognition groups: Regular Freemasonry, which insists that a volume of scripture be open in a working lodge, that every member professes belief in a Supreme Being, that no women be admitted, and that the discussion of religion and politics do not take place within the lodge; and Continental Freemasonry, which consists of the jurisdictions that have removed some, or all, of these restrictions.