Jacinda Kate Laurell Ardern (/əˈsɪndə ˈɑːrdɜːrn/; born 26 July 1980) is a New Zealand politician. She is the 40th Prime Minister of New Zealand and Leader of the Labour Party since 2017. She was elected to the House of Representatives in 2008. She has been the member of Parliament (MP) for Mount Albert since March 2017.

Ardern was born in Hamilton and grew up in Morrinsville and Murupara. After graduating from the University of Waikato in 2001, Ardern began her career working as a researcher for Prime Minister Helen Clark. She later worked in London in the Cabinet Office, and was elected president of the International Union of Socialist Youth. Ardern was first elected as an MP in the 2008 general election, when Labour lost control after nine years. She was later elected to represent the Mount Albert electorate in a by-election in February 2017.

Ardern was elected Deputy Leader of the Labour Party on 1 March 2017, after the resignation of Annette King. Just five months later, after Labour's leader Andrew Little resignation, Ardern was elected as party leader. She led her party to win 14 seats at the 2017 general election on 23 September, winning 46 seats to the National Party's 56. After working with New Zealand First, a minority coalition government with Labour and New Zealand First was formed, supported by the Green Party. Ardern became Prime Minister and she was sworn in by the governor-general on 26 October 2017. She became the world's youngest female head of government at age 37. Ardern later became the world's second elected head of government to give birth while in office when her daughter was born in June 2018.

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.