Ardern calls herself a social democrat and a progressive. Her government has focused on the New Zealand housing crisis, child poverty, and social inequality. In March 2019, she became popular because of her leadership during the Christchurch mosque shootings and for introducing strict gun laws in response. For much of 2020, she also became popular for the country's response to the COVID-19 pandemic. Ardern led the Labour Party to a historic victory in the 2020 general election, winning a majority of 65 seats in Parliament.
Ardern was born in Hamilton, New Zealand, and grew up as a Mormon. She was raised in Morrinsville and Murupara, where her father, Ross Ardern, worked as a police officer. Her mother, Laurell Ardern ( Bottomley), worked as a school catering assistant. She studied at Morrinsville College, where she was the student representative on the school's board. She later went to the University of Waikato, graduating in 2001 with a Bachelor of Communication Studies (BCS) in politics and public relations.
Ardern became interested in politics because her aunt asked her to help her with campaigning for New Plymouth MP Harry Duynhoven during his re-election campaign at the 1999 general election.
Ardern joined the Labour Party at the age of 17 and became a senior figure in the Young Labour party of the party. After graduating from university, she spent time working in the offices of Phil Goff and of Helen Clark as a researcher. She volunteered at a soup kitchen in New York City in the United States and worked on a workers' rights campaign. Ardern moved to London, England where she became a senior policy adviser for British prime minister Tony Blair. Ardern also worked at the Home Office to help with a review of policing in England and Wales.
In early 2008, Ardern was elected President of the International Union of Socialist Youth.
Ahead of the 2008 election, Ardern was ranked 20th on Labour's party list. She would soon return from London to campaign full-time for a seat in the New Zealand Parliament. She also became Labour's candidate for the safe National electorate of Waikato. Ardern lost the election, but entered Parliament as a list MP because of her high ranking in the party list. She became the youngest sitting MP in Parliament.
Opposition Leader Phil Goff promoted Ardern to the front bench, naming her Labour's spokesperson for Youth Affairs and for Justice (Youth Affairs). She made appearances on TVNZ's "Breakfast" programme as part of the "Young Guns" feature, alongside National MP and future National Party leader Simon Bridges.
Ardern ran for the parliament seat of Auckland Central for Labour in the 2011 general election, running against incumbent National MP Nikki Kaye for National and Greens candidate Denise Roche. She lost to Kaye by 717 votes. However, she returned to Parliament because of her party list ranking, on which she was ranked 13th.
After Goff resigned from the Party leadership, Ardern supported David Shearer for party leader. She was promoted to the fourth-ranking position in his Shadow Cabinet on 19 December 2011, becoming a spokesperson for social development under the new leader. Ardern ran again in Auckland Central at the 2014 general election. She again finished second, but increased her own vote and lowered Kaye's majority from 717 to 600. She was soon ranked 5th on Labour's list and because of this, Ardern still returned to Parliament where she became Shadow spokesperson for Justice, Children, Small Business, and Arts & Culture under new leader Andrew Little.
Ardern later ran for the Labour nomination for the Mount Albert by-election to be held in February 2017. The by-election was held because of the resignation of David Shearer. When nominations for the Labour Party closed on 12 January 2017, Ardern was the only nominee and was selected. On 21 January, Ardern took part of the 2017 Women's March, a worldwide protest in opposition to Donald Trump, the newly inaugurated President of the United States. She was confirmed as Labour's candidate at a meeting on 22 January. Ardern won a landslide victory, winning 77 per cent of votes cast in the preliminary results.
Following her win in the by-election, Ardern was elected as Deputy Leader of the Labour Party on 7 March 2017, after the resignation of Annette King. Ardern's vacant list seat was taken by Raymond Huo. However, Ardern would remain as Deputy Leader for exactly five months because she was elected Leader of the Labour Party in August.
On 1 August 2017, just seven weeks before the 2017 general election, Ardern became Leader of the Labour Party and also Opposition Leader, after the resignation of Andrew Little. Ardern was confirmed in an election to choose a new leader at a meeting the same day. At 37, Ardern became the youngest leader of the Labour Party in its history. She is also the second female leader of the party after Helen Clark. At first, Little had talked to Ardern on 26 July and said he thought she should take over as Labour leader, although Ardern said no and told him to "stick it out".
At her first press conference after her election as leader, she said that the upcoming election campaign would be "relentless positivity". After her appointment, the party had a large amount of public campagin donations, reaching NZ$700 per minute at its highest. When Ardern became party leader, Labour rose in opinion polls. By late August the party had reached 43 per cent as well as beating the National Party in opinion polls for the first time in over a decade. Critics said that her ideas were similar to Andrew Little's and believed that Labour's sudden increase in popularity was because of her youth and good looks.
In mid-August 2017, Ardern said that a Labour government would create a tax working group to look for the chance of increasing taxes for the wealthy and lowering them for middle-class working families. This idea became unpopular and Ardern said that her tax plan would not be pushed in a first term of Labour government. Minister of Finance Steven Joyce found that the Labour Party had a $11.7 billion "hole" in its tax policy.
The Labour and Green parties' proposed water and pollution taxes also became unpopular from farmers. On 18 September 2017, farmers and lobbyists protested against the taxes in Ardern's hometown of Morrinsville. During the protest, one farmer had a sign calling Ardern a "pretty Communist". This was criticised as sexist by former Prime Minister Helen Clark.
In the final days of the general election campaign, the National Party took a slight lead over the Labour Party.
In the 2017 general election held on 23 September 2017, Ardern was re-elected to her Mount Albert electorate seat by 15,264 votes. Preliminary results from the general election showed that Labour received 35.79 per cent of the party vote to National's 46.03 per cent. After more votes were counted, Labour increased its votes to 36.89% while National dropped back to 44.45%. Labour gained 14 seats, increasing its parliamentary representation to 46 seats. This was the best result for the party since losing power in 2008.
After the election, Ardern and Deputy Leader Kelvin Davis began talks with the Greens and New Zealand First parties about forming a coalition against National Party which did not haven enough seats for a majority. On 19 October 2017, New Zealand First leader Winston Peters agreed to form a coalition with Labour, making Ardern the next Prime Minister. The Green Party also supported the coalition. Ardern named Peters as Deputy Prime Minister and Minister of Foreign Affairs. She also gave New Zealand First five posts in her government, with Peters and three other ministers in her Cabinet.
Ardern was sworn-in as the 40th Prime Minister of New Zealand by Governor-General Dame Patsy Reddy on 26 October 2017. Ardern said that her government would be "focused, empathetic and strong".