Final results showed more than 66 percent of voters in what has been a traditionally staunchly Catholic country backed repealing the constitutional ban on terminations since 1983.
Ireland voted by a landslide to ditch its strict abortion laws in a landmark referendum hailed by Prime Minister Leo Varadkar on Saturday as a "quiet revolution", triggering scenes of jubilation in Dublin.
Final results showed more than 66 percent of voters in what has been a traditionally staunchly Catholic country backed repealing the constitutional ban on terminations.
The final results of Friday's referendum showed 66.4 percent voted for removing the constitutional ban, while 33.6 voted against.
The turnout was 64 percent.
TRT World's Simon McGregor-Wood has more from Dublin.
'A quiet revolution'
Among the 40 constituencies, the pro-choice vote peaked at 78 percent in Dublin Bay South, while rural Donegal was the only one to vote against abortion, by 52 percent.
"A quiet revolution has taken place, a great act of democracy," Varadkar tweeted.
He told cheering crowds at Dublin Castle: "The people have spoken.
"They are saying this is a country where we trust women and respect their choices.
"Thank you so much for making today possible."
His government proposes allowing abortion in the first 12 weeks of pregnancy and between 12 and 24 weeks in exceptional circumstances.
Varadkar said he wanted the law in force by the end of the year and Health Minister Simon Harris told AFP news agency that the cabinet would meet on Tuesday to approve the drafting of legislation.
'We made history'
Hugging, celebrating, singing and cheering wildly, thousands crammed into the courtyard of Dublin Castle, where the official result was declared, chanting "Yes! Yes! Yes!"
"Wonderful, wonderful, today is wonderful!" said Eileen Shields, wearing a sticker reading "We made history".
She said she was ostracised by her friends and the Church when she got pregnant outside of marriage as a teenager 46 years ago.
"I'm here because I'm 65 and in 1972 Ireland wasn't a nice place to be when you were 18 and pregnant and on your own," she told AFP.
Wearing "Repeal" tops and "Yes" badges, the crowds celebrated as the verdict was announced, waving Irish flags and placards reading "Thank you", with love hearts on.
Mass terminations since 1983
Ireland introduced a constitutional ban on abortion following a 1983 referendum. Terminating a pregnancy carries a 14-year maximum jail term.
The law was tweaked in 2013 to allow terminations if the mother's life is at risk.
The ban has led to thousands of women traveling each year to neighbouring Britain, where terminations are legal, or increasingly turning to abortion pills sold online.
Since 1983, around 170,000 Irish women have gone abroad for terminations.