The Scots most likely learned about distilling from the Irish (though they are loath to admit it). The Irish in turn learned about it, according to the Irish at least, from missionary monks who arrived in Ireland in the seventh century. The actual details are a bit sketchy for the next 700 years or so, but it does seem reasonable to believe that monks in the various monasteries were distilling aqua vitae ("water of life"), primarily for making medical compounds. These first distillates were probably grape or fruit brandy rather than grain spirit. Barley-based whiskey (the word derives from uisce beatha the Gaelic interpretation of aqua vitae) first appears in the historical record in the mid-1500s when the Tudor kings began to consolidate English control in Ireland. Queen Elizabeth I was said to be fond of it and had casks shipped to London on a regular basis.

The imposition of an excise tax in 1661 had the same effect as it did in Scotland, with the immediate commencement of the production of poteen (the Irish version of moonshine). This did not, however, slow down the growth of the distilling industry, and by the end of the 18th century there were over 2,000 stills in operation around the country.

Under British rule Ireland was export oriented and, along with grains and assorted foodstuffs, Irish distillers produced large quantities of pot-distilled whiskey for export into the expanding British Empire. Irish whiskey outsold Scotch whisky in most markets because it was lighter in body. It is said that in the late 19th century over 400 brands of Irish whiskey were being exported and sold in the United States.

This happy state of affairs for Irish distillers lasted into the early 20th century when the market began to change. The Irish distillers, pot still users to a man, were slow to respond to the rise of blended Scotch whisky with its column-distilled, smooth grain whisky component. When National Prohibition in the United States closed off Irish whisky's largest export market, many of the smaller distilleries closed. The remaining distilleries then failed to adequately anticipate the coming of Repeal (unlike the Scotch distillers) and were caught short without adequate stocks when it came. The Great Depression, trade embargoes between the newly independent Irish Republic and the United Kingdom, and World War II caused further havoc among the distillers.

In 1966 the three remaining distilling companies in the Republic of Ireland—Powers, Jameson, and Cork Distilleries—merged into a single company, Irish Distillers Company (IDC). In 1972, Bushmills, the last distillery in Northern Ireland, joined IDC. In 1975 IDC opened a new mammoth distillery at Midleton, near Cork, and all of the other distilleries in the Republic were closed down with the production of their brands being transferred to Midleton. For a 14-year period the Midleton plant and Bushmills in Northern Ireland were the only distilleries in the country.This sad state of affairs ended in 1989 when a potato-peel ethanol plant in Dundalk was converted into a whiskey distillery. The new Cooley Distillery began to produce malt and grain whiskeys, with the first three-year-old bottlings being released in 1992.Irish whiskeys, both blended and malt, are usually triple distilled through both column and pot stills, although there are a few exclusively pot-distilled brands.

Irish Pure Pot Still Whiskey is generally labeled as such. Otherwise, Irish whiskeys are a mix of pot and column-distilled whiskeys. Irish Malt Whiskey is likewise so designated. Standard Irish Whiskey is a blend of malt and grain whiskies.