After almost six years in the top job,
In a tearful speech on Thursday, Ms Ardern explained that she did not have the energy to seek re-election.
"I know what this job takes. And I know that I no longer have enough in the tank to do it justice," she said.
"I would be giving a disservice to this country knowing that I don't have enough in the tank to keep going for the next four years."
Australian Youth advocate Yasmin Poole called her "a bright light amidst the political darkness," on Twitter, adding: "Her legacy will inspire women and girls for generations."
Since Ms Ardern became prime minister in 2017, her placating demeanour and relatability have been central to her charm.
These are some of the pop-culture moments which built that legacy.
Making history with her baby at the UN
In 2017, after a short five-month residency as party leader, Ms Ardern became the world's youngest female head of government at age 37. Just over a year later, she gave birth to her daughter, becoming only the second elected leader to do so.
After wading through recurring questions about juggling motherhood in the top job - even before having her daughter Neve - Ms Ardern decided to attend the United Nations general assembly with her newborn in tow.
Jacinda Ardern holds her daughter Neve as her partner Clarke Gayford looks on during the General Assembly at the United Nations in New York in 2018. Source: AFP, Getty / Don Emmert
A catalogue of gendered questions and comments
Jacinda Ardern hit back at a question from a journalist last November after she was asked about the reasons for her meeting with Finnish prime minister Sanna Marin.
“A lot of people will be wondering: ‘are you two meeting just because you’re similar in age and have got a lot of common stuff there - when you got into politics and stuff - or can Kiwis actually expect to see more deals between our two countries down the line…?" the journalist asked.
Ms Ardern was swift to interject, asking if the media would quiz male leaders about their similarities.
"My first question is I wonder whether or not anyone ever asked [former US President] Barack Obama and [former New Zealand Prime Minister] John Key if they met because they were of a similar age," she quizzed the reporter.
The question was one of many. On the first day of her leadership, a reporter asked if she planned to get pregnant in the near future, claiming that citizens have a right to know if she will be taking maternity leave.
While she said she was open to answering the question, she defended the right for other women to have privacy.
“It is totally unacceptable in 2017 to say that women should have to answer that question in the workplace,” Ms Ardern said.
“It is a woman’s decision about when they choose to have children and it should not predetermine whether or not they are given a job or have job opportunities.”
When her daughter's bedtime coincided with her live stream
The 42-year-old Kiwi was holding an after-hours live stream on Facebook in 2021 updating New Zealanders on the country’s COVID-19 response when her young daughter interrupted.
“Mummy?”
“You’re meant to be in bed,” the prime minister replied. “It’s bedtime darling – pop back to bed and I’ll come and see you in a second.”
“Sorry everybody,” Ardern said, to the live stream. “That was a bedtime fail wasn’t it?”
She said that her mother was present that evening, and would be helping her daughter to bed, but Neve later came back, bringing it to an end.
Raising money for all the 'pricks everywhere'
Just last month, Ms Ardern had a faux-pas caught by a hot mic in parliament and was heard quietly calling the leader of the opposition party an "arrogant prick" after a disagreement.
After Ms Ardern apologised to ACT leader David Seymour for the comment, the story took a positive twist when the adversaries came together to raise money for prostate cancer.
The pair signed and framed a copy of the page in the parliament Hansard where the jibe was recorded, and it
Mr Seymour suggested the idea to Ms Ardern, who immediately agreed with placing the frame on auction.
After the rollercoaster, Ms Ardern thanked her rival for being a "good sport".
"Can’t say I expected this…..a faux pas with the old mic in parliament has turned into $100,100 for the Prostate Cancer Foundation," she wrote on Facebook.
