The first term of the Sixth Labour Government of New Zealand lasted between 2017 and 2020. It was formed on 19 October 2017 following coalition agreements between the Labour, Green and New Zealand First parties. Three years later, Labour won a landslide victory in the 2020 general election and was returned for a second term.

Formation The general election on 23 September 2017 saw the New Zealand First party hold the balance of power between National and the centre-left bloc of Labour and the Green Party. Following several weeks of negotiations with both National and Labour, New Zealand First announced on 19 October 2017 it would seek to form a minority coalition government with Labour. Confidence-and-supply support from the Greens, negotiated separately with Labour, enables the Government to have a majority in the House of Representatives.

During the coalition-forming negotiations, Labour agreed to drop its proposed water tax on farmers as part of its agreement with New Zealand First. In return, NZ First agreed to drop their demand for referendums on overturning New Zealand's anti-smacking ban and abolishing the Māori electorates. The Greens consented to a confidence and supply agreement with Labour and New Zealand First in return for several concessions, including: a referendum on legalising cannabis, treating alcohol and drugs as a health issue, net zero emissions by 2050 and requiring a climate impact assessment analysis for all legislation

2017 In November 2017, Prime Minister Jacinda Ardern and Trade and Export Growth Minister David Parker announced that their government would continue participating in the Trans-Pacific Partnership negotiations despite opposition from the Green Party. That same month, Ardern offered to resettle 150 of the asylum seekers from the former Manus Regional Processing Centre in New Zealand, but was rebuffed by the Turnbull Government in Australia. On 20 November, Ardern reaffirmed the Government's commitment to re-enter Pike River Mine with the goal of completing mine recovery by March 2019. Minister for Pike River Re-Entry Andrew Little also announced the creation of the Pike River Recovery Agency.

On 12 December, Education Minister Chris Hipkins announced that the Government would be ending National Standards in schools. This decision was welcomed by the teachers' and principals' unions but opposed by the opposition National and ACT parties. On 14 December, Finance Minister Grant Robertson released the 2017 mini-budget, with key 100-day plan policies such as the NZ$5.5 billion Families package being funded by cancelling the previous National Government's NZ$8 billion tax cuts. On 20 December, the Government established a Tax Working Group consisting of several academics, businesspeople, and senior civil servants under the leadership of former Finance Minister Michael Cullen with the goal of reforming the taxation system and alleviating the country's housing crisis. On 22 December, Prime Minister Ardern and Foreign Minister Winston Peters opposed US President Donald Trump's move to recognise Jerusalem as the capital of Israel at the United Nations General Assembly and reiterated New Zealand's support for the Two State Solution.

2018 On 19 January 2018, Ardern revealed that she was expecting her first child in June, and that Deputy Prime Minister Winston Peters would serve as Acting Prime Minister while she took maternity leave for a period of six weeks. In mid-February 2018, the Government introduced legislation to stop the creation of new charter schools but to allow the 11 existing schools to continue operating while they negotiated options with the Ministry of Education; with Ardern suggesting that the existing schools could convert to "special character" schools. In early-March 2018, during a state visit to Samoa, Ardern stated that New Zealand would be seeking to shift away from a 'donor, recipient relationship' with Pacific Islands nations in favour of forming partnerships with these states and introduced a NZ$10 million aid package to Samoa with NZ$3 million going to disaster relief following Cyclone Gita and the rest being allocated to social developmental and education projects.

On 8 March 2018, Trade Minister Parker stated the government's intention of ratifying the Comprehensive and Progressive Agreement for Trans-Pacific Partnership, an amended version of the TPP, in Chile. On 3 April 2018, Ardern and Transport Minister Phil Twyford introduced the Government's ten-year draft land transport plan which included a proposed 9-12% a litre fuel tax hike, a proposed 20% fuel tax hike in Auckland, boosting public transport funding by 46%, cutting state highway funding by 11%, and allocating $4 billion over the next ten years to establish rapid transit including light rail with an initial focus on Auckland. On 11 April 2018, Attorney General David Parker announced a government inquiry into allegations that the New Zealand Special Air Service had committed war crimes against Afghan civilians during Operation Burnham while stationed in Afghanistan.

On 12 April, the government banned future offshore oil and gas exploration in New Zealand. In addition, Energy Minister Megan Woods clarified that the thirty existing exploration permits would still continue and be unaffected by the ban. New Zealand has 27 oil fields with most being located in the Taranaki Basin. The ban on future oil and gas exploration was part of a coalition agreement between the Labour and Green parties. The decision was welcomed by Greens Co-Leader James Shaw, Greenpeace and Forest & Bird but was criticised by the Mayor of New Plymouth Neil Holdom, and the opposition National and ACT parties.

On 19 April, Little entered the Pike River Mine portal with two Pike Family representatives to demonstrate that a safe re-entry was possible. He reiterated the Government's promise to re-enter the drift in order to recover evidence and the remains of the deceased miners. On 4 May, Ardern and Housing Minister Phil Twyford stated that the Government would be investing NZ$100 million into combating homelessness. This initiative included investing NZ$37 million into building 1,500 shorter term-homes and NZ$63 million into the Housing First programme; which involves finding permanent homes for vulnerable families and treating addiction and mental health issues. On 17 May, Finance Minister Grant Robertson released the 2018 New Zealand budget, allocating NZ$2.8 billion in operational funding and NZ$3.8 billion in capital funding to the 2018 New Zealand Budget.

On 11 June, the Labour-led coalition government had abandoned efforts to repeal the Sentencing and Parole Reform Act 2010 (the so-called three-strikes law) due to internal opposition from NZ First. Ardern temporarily relinquished her duties to Winston Peters, following the birth of her child, for a period of six weeks. Peters became Acting Prime Minister on 20 June 2018, when Ardern went into labour. Her six-week maternity leave concluded on 2 August 2018.

On 1 July 2018, the government announced that it would be implementing its Families Package, which had been signed into law on 15 December 2017. The Families Package would increase paid parental leave from 22 weeks to 26 weeks from July 2020; introduce a Winter Energy Payment for beneficiaries and pensioners; paying $60-a-week to low and middle-income families with babies and toddlers; reinstating the Independent Earner Tax Credit; and increasing benefit allowances for orphans, unsupported children, and foster carers. The Families Package was criticised by the opposition National finance spokesperson Amy Adams for increasing taxation. In response, Finance Minister Grant Robertson countered that the Government was investing in low and middle-income New Zealanders rather than the "top 10% of earners". Meanwhile, Child Poverty Action Group Susan St John said that "the changes were long overdue but did not go far enough".

On 14 August, the Government passed the Overseas Investment Amendment Act 2018 which bans the sale of existing homes to non-residents as a means of easing the housing shortage in New Zealand. Australians and Singaporean nationals were made exempt from this ban due to free trade rules. The Bill was supported by Labour and its coalition partners New Zealand First and the Greens but was opposed by the opposition National and ACT parties. It passed its third reading on 14 August by 63 votes to 57 votes.

On 30 August 2018, Civil Defence Minister Kris Faafoi announced that the Government was investing into supporting "rapid response teams" in emergencies following a critical Ministerial Technical Advisory Group's (TAG) review of the Government's unsatisfactory responses to the 2016 Kaikōura earthquake and the 2017 Port Hills fires.

By September 2018, all twelve existing charter schools had been successfully converted into state integrated and special character schools. In early October 2018, the Government established a new government department called the Ministry of Housing and Urban Development to manage housing and urban development issues.

In late November 2018, Ardern and Health Minister David Clark announced that the Government would reduce the costs of visits to the general practitioner as part of their Budget 2018. These policies include extending free doctors' visits to resident children under the age of thirteen and lowering Community Service Card holders' fees by $20-$30 per visit.

On 11 December 2018, the Government passed a law, amending the Misuse of Drugs Act 1975 to allow terminally ill patients to use marijuana for palliative care. The new law was supported by all coalition parties but was opposed by the opposition National Party, which argued that it would legalise recreational cannabis consumption. On 18 December, the Government announced that it would be holding a binding referendum on legalising the personal use of cannabis during the 2020 general election.

On 19 December, the Government announced that it would be voting in favour of the UN's Global Compact for Migration. Foreign Minister Peters justified the decision on the grounds the Compact was not legally binding and would not hinder New Zealand from setting its own migration policies. The Government's decision was criticised by the opposition National Party, which claimed it would violate New Zealand's sovereignty.

2019 In mid-January 2019, Minister of Housing and Urban Development Phil Twyford admitted that the government would be unable to meet its target of building 1,000 KiwiBuild homes by 1 July, with only 33 homes being built as of 23 January. The minister estimated that the government would be able to build only 300 houses by the 1 July deadline.

On 3 February 2019, Ardern and Regional Economic Development Minister Shane Jones announced that the government had allocated NZ$100 million from its Provincial Growth Fund to supporting Māori economic development by providing access capital. It also allocated another NZ$27 million to improving transportation and the horticulture sector around Kaipara District.