The five-star Lough Eske Castle hotel in Co Donegal last year recorded profits of €1.54m.
The luxury hotel, which is part of Pat Doherty's Harcourt Developments, enjoyed the profits after revenues increased to €8.56m for the year.
Harcourt Developments finance director Nick Doherty said: "2016 was a strong year for Lough Eske where overall revenues grew by 6pc.
"Overall, in terms of geographical market share, we witnessed strong growth both from the Irish and US markets, which more than offset a slight decline in the UK market."
Total staff numbers employed at the hotel increased from 154 to 177 during the year to support this increased level of business.
Mr Doherty said: "After tax profits grew significantly during 2016 to €1.54m.
"The principal factors behind this include an improved top line revenue performance and a greater focus on cost control at the hotel."
On this year to date, Mr Doherty added: "Revenues continue to increase in 2017 whereby we are forecasting to achieve strong overall growth on last year in terms of both turnover and profitability.
"Now that the hotel has reached its 10-year anniversary and is performing strongly we are currently considering further development opportunities." Turning to the possible fallout from Brexit, Mr Doherty said: "The impact was minimal during 2016 - the level of UK business was fairly constant but as other markets grew, the UK declined slightly in terms of its market share of overall revenue."
He added: "This trend has continued in 2017 largely due to the fall in the sterling foreign exchange rate since the Brexit vote and the higher level of US visitors."