The Busker Single Grain is an Irish single grain whiskey produced at Royal Oak Distillery in County Carlow using column still distillation — the method used across Ireland and Scotland to produce lighter, smoother grain whiskeys from a mixture of malted barley and cereal grains. Column stills operate continuously and produce a spirit of high purity and relatively light character compared to pot still whiskey. The expression is matured in a combination of oak cask types including ex-bourbon barrels, producing a creamy, approachable grain whiskey with vanilla, toffee, and light cereal notes. Bottled at 44.3% ABV in the 700mL format as part of the Busker single-style trilogy.

The Busker is an Irish whiskey range produced at Royal Oak Distillery in County Carlow, a county in Ireland's Ancient East, on an 18th-century estate. The distillery was established by Illva Saronno — the Italian spirits group best known for Disaronno Amaretto — following a decision in 2014 to expand into Irish whiskey. The distillery was built on the Royal Oak estate and completed in 2015, with the first spirit produced on Easter Sunday, 27th March 2016. Royal Oak Distillery was designed from the outset to produce all three traditional styles of Irish whiskey — single malt, single grain, and single pot still — under one roof. The inaugural Busker range was released in 2020.