The boroughs of New Zealand were territorial local authorities that governed the country's urban areas, existing from the colonial period until the major local government reforms of 1989. They existed alongside the country's counties, town districts, and other territorial local authorities during that period. Boroughs with over 20,000 population could be granted city status.
When New Zealand became a British colony in 1840, the Colonial Office tasked Governor William Hobson with promoting the establishment of local municipal and district government within the colony through the issuing of proclamations. The Municipal Corporations Ordinance 1842 was the first legislative attempt at this, with the Ordinance stating that any district with a minimum of 2,000 residents could become a borough, meaning a council could be elected with powers to set rates for the provision of roads, water infrastructure, and jails. Suffrage was open to all adult men not just landowners. Issues arose when the colonial government found that the ordinance limited their ability to build lighthouses; for this and other reasons the ordinance was disallowed in 1843.
Six provinces were established in New Zealand in 1852; these provinces would pass various ordinances establishing their own system of boroughs, though almost all were established in the prosperous Otago Province. The provinces were abolished in 1876.
An act titled the Municipal Corporations Act 1876 established a colony-wide system of municipal government, to exist alongside a system of counties established in separate legislation.
The Local Government Act 1974 sought to rationalise local government, attempting to tackle the problem whilst dealing with staunchly independent local authorities. The Act abolished the distinction between boroughs and counties, and allowed for the creation of regional units of government. The Act also increased the powers of the Local Government Commission.
In 1989, the Fourth Labour Government enacted major reforms to local government, under the provisions of the Local Government Act 1974. Around 850 local authorities were amalgamated together into 86, with many boroughs amalgamating with their surrounding rural areas to form district councils.
Under the Municipal Corporations Act 1954, boroughs with at least 20,000 people could be granted city status.