Almost four million overseas visitors came to Ireland in the first six months of the year - a jump of 11%.
The number represents a boost to the economy of €1.9bn - an increase of €165m compared to the same period last year.
Tourism Ireland said the results reflected the upbeat sentiment of those in the industry here and abroad.
Chief Executive Niall Gibbons said: "We've seen very strong growth over the last four to five years. (However,) we expect those rates of growth to moderate, and we need to be conscious too of the possible effects of Brexit in the coming years."