The most popular beer in Ireland is Guinness.

An excerpt from the article 39 facts about Ireland

It is a dark, top-fermented stout beer. The beer is brewed in the brewery founded by Arthur Guinness, St. James's Gate Brewery in Dublin. In 1833, the company was Ireland's largest brewery, and half a century later it was producing one million barrels of beer a year. Guinness's symbol is the golden harp, which is the coat of arms of Ireland.

The famous Guinness Book of Records was created in 1955 on the initiative of Hugh Beaver, then general director of the St. James's Gate Brewery.

The Guinness Storehouse operates within the brewery - a tourist attraction that has been visited by over 9 million guests since 2000. Research results suggest that Guinness may have an effect similar to aspirin and prevent the formation of blood clots that lead to a heart attack.