The Tullamore Distillery was founded in 1829 by Michael Molloy in Tullamore, County Offaly, a region known for its grain cultivation. Later, Tullamore DEW Whiskey was produced by Irish Distillers in Midleton, where modern production facilities and high quality standards were used.

Since 2010, the brand has belonged to the Scottish distillery group William Grant & Sons, which also owns Glenfiddich. Today, the whiskey is produced in a modern distillery near Tullamore, which was opened in 2014. This facility combines traditional production methods with modern technology to ensure the high quality of Tullamore DEW whiskey.

The Tullamore distillery is expanding its product range with a very special whiskey. They have developed the first Irish whiskey to be matured in cider casks. After conventional ageing in bourbon and sherry casks, Tullamore is given its unique finish in former cider casks.