Operating profits at John Teeling's Great Northern Distillery soared 36% to €7.6m (£6.4m) in its last financial year as turnover at the business surged.
Newly-filed accounts for the company show that revenue hit €19.2m (£16.2m) in the 12 months to the end of last April, compared to €13.6m (£11.5m) in the previous year.
The distillery, which operates on the site of the former Harp brewery in Dundalk, operates stills that produce a range of whiskey spirits. It also operates a small-scale gin still.
The Harp brewery site was closed and sold by Diageo in 2013.
The main markets for the whiskies are own label, while it also undertakes contract distilling and private label production.
The distillery is owned by Mr Teeling, his sons and managers who were the former management team at Cooley Distillery.