An electorate or electoral district (Māori: rohe pōti^[1]) is a geographic constituency used for electing a member (MP) to the New Zealand Parliament.^[2] The size of electorates is determined such that all electorates have approximately the same population.

Before 1996, all MPs were directly chosen for office by the voters of an electorate. In New Zealand's electoral system, 72 of the usually 120 seats in Parliament are filled by electorate members, with the remainder being filled from party lists in order to achieve proportional representation among parties. The 72 electorates are made up from 65 general and seven Māori electorates. The number of electorates increases periodically in line with national population growth; the number was increased from 71 to 72 starting at the 2020 general election.

The Electoral Act 1993 refers to electorates as "electoral districts".^[2] Electorates are informally referred to as "seats" (Māori: tūru), but technically the term seat refers to an elected member's place in Parliament.^{[3][n 1]}

As of 2018^[update] the Representation Commission determines electorate boundaries.^[4] The Commission consists of:

• Four government officials—the Government Statistician, the Surveyor-General, the Chief Electoral Officer, and the Chairperson of the Local Government Commission.
• A representative of the governing party or coalition, and a representative of the opposition bloc.
• A chairperson (often a judge) nominated by the other members (with the exception of Chairperson of the Local Government Commission).^[4]

The Representation Commission reviews electorate boundaries after each New Zealand census, which normally occurs every five years.^[2] The South Island is guaranteed to have 16 general electorates, and dividing the number of persons in the South Island's general electoral population by 16 determines the South Island Quota which is then used to help calculate the number of Māori electorates and to determine the number of North Island electorates. The number of Māori electorates is influenced by the Māori Electoral Option where Māori voters can opt to be in either a Māori electorate or a general electorate. The percentage of Māori voters opting for the Māori roll determines the percentage of the whole Māori population (of persons claiming Māori ancestry at the previous census) which is then divided by the South Island Quota to calculate the number of Māori electorates. South Island Māori opting for the general roll are included in the population on which the South Island Quota is established. The North Island population (including Māori opting for the general roll) is divided into electorates, each of approximately the same population as the South Island ones.^[5] Electorates may vary by no more than 5% of the average population size.^[2] This has caused the number of list seats in Parliament to decline as the population is experiencing "northern drift" (i.e. the population of the North Island, especially around Auckland, is growing faster than that of the South Island) due both to internal migration and to immigration.^[6]

Although the New Zealand Parliament is intended to have 120 members, some terms have exceeded this quantity. Overhang seats arise when a party win more seats via electorates than their proportion of the party vote entitles them to; other parties are still awarded the same number of seats that they are entitled to, which results in more than 120 seats in total.^[7] In 2005 and 2011, 121 members were elected; 122 members were elected in 2008.^[8]

The Representation Commission determines the names of each electorate following the most recent census.^[4] An electorate may be named after a geographic region, landmark (e.g. a mountain) or main population area. The Commission adopts compass point names when there is not a more suitable name. The compass point reference usually follows the name of the main population centre, e.g. Hamilton East.

Over the years, there have been two types of "special" electorates created for particular communities. The first were special goldminers' electorates, created for participants in the Otago Goldrush—goldminers did not usually meet the residency and property requirements in the electorate they were prospecting in, but were numerous enough to warrant political representation. Two goldminers' electorates existed, the first began in 1863 and both ended in 1870.

This table shows the electorates as they were represented during the 54th New Zealand Parliament.