Almost 4.3 million people travelled to Ireland during the first half of the year, according to the Central Statistics Office.
That represents a 9.9% increase on the same period of 2013 and is a near-15% improvement on figures for the first six months of 2011.
During the three months to June alone there was an 11.1% increase in the number of trips made to Ireland, according to the figures, with more than 2.3m trips to the country being made during that period.
More than a third of visitors during that time – 836,700 – were British residents, an increase of 8.5% on the same quarter of 2013.
Another third – 833,800 – were residents of another European country, which was an increase of 9.7% on last year.
Meanwhile trips by residents of North America saw the greatest percentage growth, with 488,100 coming to Ireland during the three months – 16.6% more than in the May to July period of 2013.
Trips by Irish residents to other countries fell by 0.7% to 1,985,800 during the three months to July, but was up marginally in the first six months overall.