Ratings agency Standard and Poor's raised Ireland's credit rating to "A", citing the country's improved economic growth forecast and its repayment of debt.
The move to "A" from "A-" was the second time in six months that the ratings agency has upgraded Ireland, which was stripped of its maximum "AAA" rating amid the financial crisis in 2009 and a subsequent EU-IMF bailout.
"The upgrade reflects our view of Ireland's solid economic growth prospects, which we expect to underpin further improvements in the government's budgetary position," Standard and Poor's said in a statement.
Now the fastest growing in the eurozone, Ireland's economy is forecast to grow almost five percent this year, a significant rebound that contrasts with sluggish growth in much of the bloc.
Standard and Poor's forecast that Ireland would grow an average of 3.7 percent between 2014 and 2016.
It forecast unemployment would fall to nine percent in 2017, the lowest level since 2008, and said the labour market was flexible due to emigration and wage adjustments.
The ratings agency noted that Ireland's banking sector had strengthened and that the state-run body NAMA that bought bad loans from banks had made good progress.
Finance minister Michael Noonan welcomed the news, which came ahead of meetings with investors in China, saying the upgrades "reopened new markets to us across Asia".
"The Standard and Poor's upgrade is further evidence that our economic recovery has firmly taken hold thanks to the policies pursued by this government and the commitment of the Irish people," Noonan said.