By multimedia producer Suzanne Elliott
Mr Hipkins, 44, has promised Kiwis he will bring a back-to-basics approach - focusing on the economy and what he described as the “pandemic of inflation.”
He will have less than nine months before contesting what is likely to be a tough general election, with opinion polls indicating his left-wing Labour Party is trailing its key rival, the conservative National Party, led by Christopher Luxon.
Governor-general Cindy Kiro, the King's representative in New Zealand, officiated the brief swearing in ceremony in front of his friends and colleagues after she earlier accepted Ms Ardern's resignation.
“This is the biggest privilege and responsibility of my life,” Mr Hipkins said at the ceremony. “I'm energised and excited by the challenges that lie ahead.”
Carmel Sepuloni was also sworn in as deputy prime minister, the first time a person of Pacific Island heritage has taken on the role.
After the ceremony, Mr Hipkins said: “It feels pretty real now.”
Who is Chris Hipkins?
Mr Hipkins was born in the Hutt Valley, which borders the capital Wellington, in 1978. He entered Parliament as an MP in 2008 alongside fellow future star Ms Ardern.
Nicknamed 'Chippy,' Mr Hipkins became a social fixture around the 'Beehive', the distinctive parliamentary building at Wellington's political heart.
His love for sausage rolls became so well-documented he was presented with a "sausage roll cake" for his birthday last year by police officers.
Mr Hipkins is, according to biography, an "outdoor enthusiast" and particularly keen on "mountain biking, tramping (hiking) and swimming".
As his star rose, he came known for his relaxed dress sense as much as for his trademark sense of humour.
The casual hoodie, 'Hutt-issue headgear' wraparound sunglasses and cap he wore to meet the media at the weekend ahead of his swearing-in ceremony caught Kiwis' attention.
The outfit was later auctioned off by the Labour party for $5,000 (£2,610) on Monday.
Mr Hipkins is a father-of-two, and took extended parental leave after the birth of his second child in 2018, becoming one of New Zealand's first male cabinet ministers to do so.
In his first press conference after he was confirmed Labour's new leader, he confirmed he had been living separately from his wife for a year, in order to quell speculation about his private life.
"A year ago, my wife and I made the decision that we would live separately, that we would do everything we can to raise our children together," he said.
"We remain incredibly close. She's still my best friend. But we have made that decision in the best interest of our family.”
Mr Hipkins served as education and police minister under his predecessor but rose to public prominence during the pandemic when he was made Covid-19 response minister.
During his 15 years in politics, he has become known as a political trouble-shooter who has taken on a variety of roles to try to iron out problems created by other politicians.Mr Hipkins is considered more centrist than Ms Ardern and colleagues hope that he will appeal to a broad range of voters, as the Labour party faces a fight for survival within months.
A self-styled "straight shooter", Mr Hipkins has put his foot in his mouth more than once.
During one of New Zealand's lockdown, he told people during a virus lockdown that they could go outside and “spread their legs," (instead of stretch,) a comment that drew mirth at home and abroad.
He poked fun at his slip of the tongue when he later attended a press conference with a mug which read “spread your legs, not the virus”.
Posting a picture of himself and the governor-general at Tuesday's ceremony, he reminisced about another on-air slip.
"Back in 2017 when I was first sworn in as a minister I made a joke as the governor-general signed my warrant that it was going 'straight to the pool room'," he recalled, referencing the catchphrase from cult-classic Australian film, The Castle.
"I didn’t realise all the microphones were live and it got picked up in the media," he added, assuring he would be "far more restrained" this time around.
His unusual - and late - entrance to deliver a Covid update to the media during the pandemic, when he emerged from bush near a beach resort also caused a stir.
The-then Covid response minister was holidaying with his family near the coast when he became stuck in traffic after returning home to fetch a suit.
His mother, Dr Rosemary Hipkins, apologised to the waiting media for her son's lateness.
Whether his prime ministership runs for more than nine months remains to be seen - despite lagging behind the opposition in the polls, Mr Hipkins said he believed his party could win the election.
New Zealand operates a Mixed Member Proportional (MMP) voting system, which results in political parties frequently forming coalitions rather than governing alone.
Jacinda Arden bids farewell Ms Ardern made her final official appearance as prime minister after her shock resignation last week after more than five years in the role.
Standing down ahead of Mr Hipkins' swearing in ceremony, Ms Arden said the thing she would miss most was the people because they had been the “joy of the job.”
On Wednesday morning, she was greeted with hugs and farewells by dozens of former staff and admirers on Parliament's forecourt as she left the building.
Ms Ardern plans to stay on as a backbencher until April to avoid triggering a special election ahead of the nation’s general election in October.
The Prince and Princess of Wales thanked Ms Ardern on Twitter “for your friendship, leadership and support over the years, not least at the time of my grandmother’s death. Sending you, Clarke and Neve our best wishes. W & C”
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