Applause in Parliament and celebrations throughout the country greeted the vote by MPs legalising same-sex marriage.
The Marriage (Definition of Marriage) Amendment Bill passed its third and final reading in Parliament by 77 votes to 44 on Wednesday night. The vote made New Zealand the first country in the Asia-Pacific region and the 13th in the world to enshrine marriage equality in law.
The legalisation amends the Marriage Act so that two people - regardless of their sex, sexual orientation or gender identity - can marry.
The public galleries in Parliament's debating chamber were packed - so much so that the old legislative chamber had to be opened to the public, and that too was standing room only.
The bill's sponsor, Labour MP Louisa Wall, says she has a great sense of satisfaction and pride over the change.
"What's happened with society I think is that we've evolved from segregating a community within our wider New Zealand community from being fully accepted and being able to fully participate."
Ms Wall told Radio New Zealand's Morning Report programme much of the pressure for change came from young people.
At a celebration in an Auckland bar, Sergio Lopez said the passing of the bill allows him and partner Colin Ennor to plan the rest of their lives together. "I'm super happy, I'm super excited, that's all that I want."
Gay rights advocate David celebrated among hundreds of others in Auckland's central city and said the law change has been a long time coming. "This makes us real, we are who we are."
Wellington couple Kelly Purcell and Mariken van Laanen who have been together for four years say they will now marry in November, rather than having a civil union as they had planned.
"Most of it is about choice. (Marriage and civil unions) are not the same, and we just want to have the ability to choose just like everyone else," Ms van Laanen told Morning Report.
Ms Purcell said the couple also want to be able to adopt if they choose to do so.
One of those who opposed the measure, Labour MP Su'a William Sio, said there was strong, silent opposition from Invercargill to Auckland.
"Marriage between a man and a woman at the exclusion of all others is a fundamental belief by many of the churches, not just Christians - it includes Muslim, Jewish, Hindu and others."
The Catholic Bishop Auckland, Patrick Dunn, said many people oppose the law change and it was a sad day for New Zealand. "I hope there will not be implications that will further undermine and destablise society as such," he said.
Listen to Louisa Wall
Australian couples plan to marry in NZ
The Australian Marriage Equality lobby group says hundreds of same-sex Australian couples are now planning to head to New Zealand to tie the knot.
National convener Rodney Croome expects as many as 1000 gay couples will now cross the Tasman to get married.
Mr Croome said the New Zealand decision will be a game changer in terms of pressuring Australian politicians to take similar action.