The Central Statistics Office (CSO) has released figures showing that the first quarter of the year saw a 22% increase in the number of American visitors over the same period last year.
The figures confirm a strong increase of 6.7% in visitors who stayed overnight in the Republic of Ireland in the first three months of the year - an additional 71,000 visitors.
There was also a strong recovery in long haul travel (+42%), which last year suffered badly from the impact of SARS.
The figures showed that Australia and Asian markets have performed particularly strongly according to Tourism Ireland.
Visitor numbers from Continental Europe increased by 4.4% and from Great Britain by 2.4%.