Growth in the country's services activity hit a four-month high in May as the sector continued to recover from a brief slowdown in March that followed some of the worst winter weather in nearly 30 years.
The latest Investec Services Purchasing Managers' Index (PMI) rose to 59.3 from 58.4 in April.
The index has remained above the 50 mark that separates growth from contraction since August 2012.
The services sector covers areas as diverse as communication, financial and business services, IT and the tourism trade.
Growth in the level of new business from abroad hit a two-year high for the second month in a row, climbing to 59.5 from 59.2, with a number of panellists noting higher new orders from British clients.
Given its close trading links with the UK, Ireland is seen as the EU member state most at risk from Brexit. But so far the economy looks set to be the fastest growing in the bloc for a fifth year in a row.
A survey published last week showed Irish manufacturing growth improved in May as the rate of new orders accelerated sharply.
"Taken together with last Friday's Investec Manufacturing PMI, the May PMI reports suggest that growth in activity across much of the private sector in Ireland has rebounded after the weather inspired softness that was seen in Q1 2018," Investec Ireland's chief economist Philip O'Sullivan said.
