The town is thought to have been named after Westport, County Mayo in Ireland, although the choice of name was no doubt also guided by the town's location. The population of the Westport urban area was 3,900 in the 2006 census, an increase of 117 from 2001. Including the surrounding area of Orowaiti, the 2006 population was 4,512. The Buller District Council gives a 2007 population of about 5,000.
There is evidence that Māori settlers lived in the Buller (Kawatiri) area from very early on. The settlers appeared to live mostly coastal lives, though they explored the mountains for pounamu (jade or greenstone), which they then traded with other iwi.
The first wave of European settlers came to Westport in 1861 as gold miners, and the first European vessel known to have entered the river was the sealing schooner Three Brothers in 1884. The 1880s saw many exploratory parties of geologists and surveyors combing the area for the presence of valuable resources and taking the measure of the land. Amongst them were Charles Heaphy, William Fox and Thomas Brunner. While gold brought initial interest to the area, and for example, led to large areas of the coastal areas (covered by sediment from the river) being dredged for the valuable mineral, the area soon became much more famous for coal mining, still a dominant concern in the region today.
During the period, 1853 to 1876, Westport was administrated as part of the Nelson Province.
The first railway of the area in 1864 ran from Westport 18 kilometres (11 mi) to the coal fields, most of them north of town. The first section of railway from Westport to Fairdown via Sergeants Hill opened on 31 December 1875; this line ultimately reached Seddonville in 1895 and was known as the Seddonville Branch. From this beginning, an isolated network of branch lines was developed and it was not linked to the national network until the completion of the Stillwater–Westport Line through the Buller Gorge in 1942.
The Westport climate is strongly influenced by the high amount of precipitation from the Tasman Sea, with all months except February being rather wet on average. Despite very high annual rainfall, Westport is often prone to drought and conservation measures are sometimes triggered. While colder than the more northern parts of New Zealand, average temperature changes over the year are not extreme.
Economic activity is based around fishing, coal mining and dairy farming. Historically, gold mining was a major industry, and coal mining was much more extensive than today (especially in terms of employment numbers). However, the region still is home to New Zealand's largest opencast mining operation in Stockton. Some native forest logging occurred in the area until cessation around 1999. The Holcim company had a large cement plant in the southwest side of town until its closure on 30 June 2016.
Tourism has some famous destinations in this area, such as the Oparara Basin Arches, and Cape Foulwind with its large fur seal colony (on Tauranga Bay and Buller Bay as well). For other wildlife such as whales and dolphins:
Rafting and jetboating in the Buller Gorge are also popular. Many South Island visitors do however pass by this quieter area, opting instead to go to Abel Tasman National Park, to Hanmer Springs or, if they do visit the West Coast, to Greymouth and the Fox- and Franz Josef glaciers further south. Westport is also a base for trips to Karamea, with the only road access to the area running north from near Westport.
The "Coaltown Museum" in Westport illustrates the history of the Buller District.
A daily local newspaper is published in Westport, the Westport News. The Westport News building also houses coast-wide local radio station Coast FM.
The town used to have one cinema / theatre, the St James Theatre, able to seat 424 patrons for film screenings, theatre productions or other activities. After being found structurally unsound, the theatre had to be demolished. A new theatre has since opened. The NBS theatre has two movie theatres, one which seats 55 people and a boutique theatre that seats approximately 20 people. This theatre also has a large facility with seating for approximately 370 people and a stage for performing.
The Holcim company manages the day-to-day operations of Westport's port, using it to ship their cement product to market, for example to the Port of Onehunga in Auckland.
Westport Airport is a small airport. It was formerly served twice daily on weekdays and daily in the weekend by Air New Zealand from Wellington, and prior to that, flights to Christchurch and Hokitika were also operated. The Air New Zealand service from Wellington service ceased in April 2015 and its place was taken by Sounds Air.
The township also has a links-style, 18-hole, par-72 golf course. The course measures around 5,600 metres (18,400 ft) with medium to narrow fairways and small "target" greens.
The Solid Energy Centre, a sports complex, was opened on 18 April 2009.
Buller High School is a secondary (years 9–13) school with a roll of 336. The school celebrated its 75th anniversary in 1997 but also claims to have been operating for over 100 years, due to its connection to earlier secondary schooling in the district.
Westport North School and Westport South School are full primary (years 1–8) schools with rolls of 198 and 307, respectively. The schools were founded in 1942 and 1941
St Canice's School is a full primary (years 1–8) school with a roll of 140. It is a state integrated Catholic school and has operated since at least 1882.
All these schools are coeducational. All have a decile rating of 4, except Buller High School, which has a decile of 3. School rolls are as of July 2017.