The uilleann pipes, originally known as the Union pipes, are the characteristic national bagpipe of Ireland. The uilleann pipes bag is inflated by means of a small set of bellows strapped around the waist and the right arm. Found in other European bagpipes (ex. Northumbrian pipes, Scottish smallpipes), the bellows not only relieves the player from the effort needed to blow into a bag to maintain pressure, they also allow relatively dry air to power the reeds, reducing the adverse affects of moisture on tuning and longevity. Some pipers can converse or sing while playing as well.

The uilleann pipes are distinguished from many other forms of bagpipes by their sweet tone and wide range of notes; the chanter has a range of two full octaves, including sharps and flats, together with the unique blend of chanter, drones, and "regulators." The regulators are equipped with closed keys which can be opened by the piper's wrist action enabling the piper to play simple chords, giving a rhythmic and harmonic accompaniment as needed.