Ireland's become the first country in the world to approve gay marriage in a popular vote.
Just over 62% supported changing the constitution - with more than 1.2 million people turning out in support of marriage equality.
The turnout percentage at 60.5% was one of the highest ever for a referendum - and the number of votes cast - 1.95 million - is an electoral record.
Just before 7pm returning officer Ríona Ní Flanghaile made the official declaration:
Just one constituency in the country voted No - Roscommon South Leitrim.
The highest yes vote was in Dublin South East with 74.91% - the narrowest victory came in Donegal South West at 50.05% where just 33 votes extra were cast in favour.
Campaigners took to the streets of Dublin to celebrate:
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These 'YES' campaigners in Dublin are overjoyed at the result:
Reacting tonight Taoiseach Enda Kenny said it was a historic day:
Tanaiste Joan Burton says it's been an uplifting campaign to create a "Rainbow Nation":
Tonight the celebrations are ongoing in Dublin and around the country, but the first same sex marriages are some months off - the Health Minister Leo Varadkar's promised the legislation necessary will be passed by July allowing for marriages by the autumn.