The official result for the marriage equality referendum was declared at Dublin Castle shortly before 7pm this evening, with the final tally ending up 62.1 pc Yes against 37.9 pc No.
In total, almost two million people voted.
The number of Yes votes cast was 1,201,607, with 734,300 No.
Some 13,818 votes were marked as invalid and so were not counted towards the final result.
Over all, the Yes vote secured a 467,307 majority.
Large crowds have gathered at Dublin Castle to celebrate the resounding Yes.
Speaking after the official result was announced, Taoiseach Enda Kenny said Ireland had made history today.
"Our people have truly answered Ireland's call... we have made history."
Adding: "Those who voted no did so due to genuine held views which should be respected."
Meanwhile, Archbishop of Dublin Diarmuid Martin called the Yes result a "reality check" for the Catholic Church in Ireland.
“I think it’s a social revolution. It’s a social revolution that didn’t begin today, it’s a social revolution that’s been going on, and perhaps people in the church have not been clear in their understanding of what that involves," he said.
The hashtag 'We Made History' trended on Twitter as elated Irish people took to social media to express their delight at the official result.
Based on a final poll of 1,949,725, more people voted in the same-sex marriage referendum than in any other since the foundation of the State.
The first official constituency result was declared in Sligo-North Leitrim with 53.57 pc voting Yes.
Only Roscommon-South Leitrim voted No.
The results there saw voters reject marriage equality by 51 pc to 49 pc.
The tightest margin was in Donegal South West where it was Yes by only 33 votes.
The official result for the marriage equality referendum was declared at Dublin Castle shortly before 7pm this evening, with the final tally ending up 62.1 pc Yes against 37.9 pc No.
