New Zealand is a representative democracy in which members of the unicameral New Zealand Parliament gain their seats through elections. General elections are usually held every three years; they may be held at an earlier date at the discretion of the prime minister, but that usually only happens in the event of a vote of no confidence or other exceptional circumstances. A by-election is held to fill an electorate vacancy arising during a parliamentary term. The most recent general election took place on 14 October 2023.

The New Zealand electoral system has been mixed-member proportional (MMP) since the 1996 election. MMP was introduced following a referendum in 1993. It replaced the first-past-the-post (FPP) system New Zealand had previously used for most of its history. Under MMP, New Zealanders have two secret ballot votes to elect members of Parliament (MPs). The first vote is for a candidate from an electorate, a geographic electoral district. The second is the party vote for the political party the voter wants to form the government.