Voters will elect 120 members to the House of Representatives under New Zealand's mixed-member proportional (MMP) voting system, a proportional representation system in which 72 members are elected from single-member electorates and 48 members are elected from closed party lists. As of September 2020, around 3.36 million people (89.2%) are registered to vote in the election, out of an estimated eligible population of 3.77 million.

After the previous election, the centre-left Labour Party, led by Prime Minister Jacinda Ardern, formed a minority coalition government with the New Zealand First party, with confidence and supply from the Green Party. The main opponent to the Labour–NZ First government is the centre-right National Party, led by Judith Collins. ACT New Zealand is the sole other party in Parliament, represented by a single MP. It will be the second general election (the first being 1999) where both major parties have female leaders.

A referendum on personal cannabis consumption is planned to be held at the same time, along with a referendum on euthanasia due to the End of Life Choice Act passing its third reading in parliament.