The 25-year-old Northern Irish star has agonized for months over whether to represent Ireland or Great Britain at Rio 2016 when golf returns to the Olympics after a 112-year absence.
The golf ace was so torn about which country to pin his allegiances to and the resulting controversy that he feared may follow, he had even considered not taking part in the next Olympics.
But yesterday, on the eve of the Irish Open in Cork, he said had finally made his decision and was warmly applauded when he revealed he will try to win Gold for Ireland in Brazil in two years' time.
Speaking at a pre-tournament press conference at Fota Island in Cork, he said that past experience of representing Ireland in team events at junior and amateur level under an all-Ireland golf banner had been the deciding factor.
He said: "I've been thinking about it a lot. I don't know whether it's been because the World Cup has been in Brazil and I've been thinking a couple of years down the line.
"Thinking about all the times that I played as an amateur for Ireland and as a boy and everything, I think for me it's the right decision to play for Ireland in 2016."
McIroy - who was raised a Catholic but had a golfing base and home in Holywood, a predominantly Protestant area in suburban Belfast - has been tormented by which nation to pin his colours to for at least two years.
RTE notes that he has previously spoken of being in an "extremely sensitive and difficult position" over the decision, releasing an open letter on his Twitter account in September 2012 in response to quotes attributed to him which said he felt "more British than Irish".
And when quizzed yesterday about how anxious he had been about the matter, he replied: "More worried about what other people would think, rather than me. But you've got to do what's right for yourself and what you feel most comfortable with, and ultimately that was the decision that I made.
"I was always very proud to put on the Irish uniform and play as an amateur and as a boy, and I would be proud to do it again.
"Just because now that I'm playing golf for money and I'm a professional, I'm supposed to have this choice or decision to make, where if you look at rugby players, you look at cricketers or hockey players, they view Ireland as one, the same as we do in golf [note, players of those sports represent an all-Ireland team].
"I don't think there's any point to change that or go against that just because it's a different event or it's the Olympics.
"I've had a lot of time on my own the last few weeks and just been thinking about it a lot. It's something that's been quite important to me and something that I needed to make some sort of decision or some sort of stand on it.
McIlroy, who recently broke off his engagement to Danish tennis ace, Caroline Wozniacki, added: "Just weighing up everything, and thinking about the times that I played for Ireland and won the European Team championship with Ireland, won a lot of amateur titles representing Ireland, I just thought why change that? Basically it's just a continuation of what I've always done."
McIlroy's decison brought a big smile to the face of OCI [Olympic Council of Ireland] President, Pat Hickey.
He said: "His [Rory's] amazing talent, brilliant personality and endless energy will give all our athletes a huge boost. He is an iconic figure in world sport and will be warmly welcomed by all the Irish team members, no matter what sport they represent. This is great news for Ireland's medal prospects for Rio 2016."
McIroy's compatriot, Graeme McDowell - who has already declared for Ireland at the next Olympics - welcomed the news, adding that he himself had suffered no negative reaction whatsoever.
And Michael Ring, Ireland's state minister for tourism and sport, said: "To have a two-time major winner declaring for Ireland is superb and will surely improve our medal hopes."