New figures from the Central Statistics Office show that trips to Ireland by overseas residents increased by 8.7% to reach a total of 1,025,600 in May.
The CSO said that trips by UK residents here increased by 12.4% to 349,900, while trips by residents of other European countries were up 12.4% to 385,300.
Today's figures also reveal that visits here by residents of the US and Canada were up 9.8% to 234,700 trips. But trips from Other Areas, however, saw a 5.9% decrease to 55,800.
Meanwhile, trips by Irish residents overseas saw a 9.7% increase to 1,736,900 trips in May of this year compared to the same time last year.
Overall, the CSO said the number of overseas visitors increased by 7.6% during the months of January to May when compared with the first five months of 2017.
Commenting on today's CSO figures, the chief executive of Tourism Ireland Niall Gibbons said that 273,300 additional overseas arrivals came here in the first five months of 2018 compared with the same time last year.
Mr Gibbons noted that while UK visitors were up 2.4%, it was too early to say if this represented a turnaround in the long-term trend.
He said the impact of Brexit on outbound travel from Britain remains a concern.
"The fall in the value of sterling has made holidays and short breaks here more expensive for British visitors and has made Britain more affordable for visitors from many of our top markets. Competitiveness and value for money remain more important than ever in Britain this year," he cautioned.
But looking to the rest of the year, Mr Gibbons said the air and sea access picture is very positive for the tourism industry, with increases in the number of airline seats from Britain, Mainland Europe, North American and long-haul markets.
"We look forward to seeing the impact of new long-haul flights on Irish tourism this summer - including the new Aer Lingus service from Seattle to Dublin, which began last month, as well as the Hainan Airlines flight from Beijing and the Cathay Pacific flight from Hong Kong, which both kicked off earlier this month," he added.
