Bluff (Māori: Motupōhue), previously known as Campbelltown and often referred to as "The Bluff", is a town and seaport in the Southland region, on the southern coast of the South Island of New Zealand. It is the southernmost town in mainland New Zealand and, despite Slope Point and Stewart Island being further south, Bluff is colloquially used to refer to the southern extremity of the country (particularly in the phrase "from Cape Reinga to The Bluff").^[4] According to the 2018 census, the resident population was 1,797, a decrease of 6 since 2013.^[5]

The Bluff area was one of the earliest areas of New Zealand where a European presence became established. The first ship known to have entered the harbour was the Perseverance in 1813, in search of flax trading possibilities, with the first European settlers arriving in 1823 or 1824.

This is the foundation for the claim^[6] that Bluff is the oldest permanent European settlement in the country. However, the missionary settlement at Kerikeri was both earlier and larger. The town was officially called Campbelltown in 1856, became a borough in 1878, and was renamed Bluff in 1917.^[7]

Bluff is 30 km (20 mi) by road from Invercargill, and the southern terminus of the Bluff Branch, the continuation from Invercargill of the Main South Line. This was one of New Zealand's earliest railways, opening on 5 February 1867.^[8]

Bluff is at the end of a peninsula that forms the western side of Bluff Harbour and Awarua Bay, with the port located in the relatively narrow entrance channel. It is on State Highway 1, which terminates one kilometre to the south of the town at Stirling Point. At Stirling Point, there is "the town's biggest tourist attraction",^[9] a signpost showing the distance and direction to various major cities and locations around the world, including the Equator and the South Pole. The signpost was corrected in late 2018, after a Scottish tourist pointed out in 2017 that there were some errors.^[10]

Bluff is dominated by Bluff Hill / Motupōhue (standing at 265 m (870 ft)), which provides some shelter from the prevailing westerly winds. There is a path along the shore through native bush up to this point. The town is named for this bluff, which was known to early whalers as Old Man's Bluff or Old Man Bluff. East across the entry channel from Bluff is Tiwai Point, home to New Zealand's only aluminium smelter and its wharf. Alumina is shipped from Australia and electricity is supplied by the Manapouri Power Station in Fiordland National Park.

A chain sculpture on the coast near Bluff symbolises the Māori belief that Stewart Island is anchored to South Island; a similar sculpture in Rakiura National Park represents the other end of the chain.

Bluff covers 10.14 km² (3.92 sq mi)^[2] and had an estimated population of 1,840 as of June 2023,^[3] with a population density of 181 people per km².

Bluff had a population of 1,797 at the 2018 New Zealand census, a decrease of 6 people (−0.3%) since the

2013 census, and unchanged since the 2006 census. There were 780 households, comprising 918 males and 879 females, giving a sex ratio of 1.04 males per female. The median age was 47.3 years (compared with 37.4 years nationally), with 330 people (18.4%) aged under 15 years, 228 (12.7%) aged 15 to 29, 858 (47.7%) aged 30 to 64, and 381 (21.2%) aged 65 or older.

Ethnicities were 77.6% European/Pākehā, 46.4% Māori, 6.2% Pasifika, 1.3% Asian, and 1.5% other ethnicities. People may identify with more than one ethnicity.

The percentage of people born overseas was 6.0, compared with 27.1% nationally.

Although some people chose not to answer the census's question about religious affiliation, 54.9% had no religion, 32.7% were Christian, 1.0% had Māori religious beliefs, 0.2% were Hindu, 0.2% were Muslim, 0.5% were Buddhist and 1.0% had other religions.

Of those at least 15 years old, 102 (7.0%) people had a bachelor's or higher degree, and 528 (36.0%) people had no formal qualifications. The median income was $30,500, compared with $31,800 nationally. 189 people (12.9%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 726 (49.5%) people were employed full-time, 228 (15.5%) were part-time, and 45 (3.1%) were unemployed.^[11]

South Port is the port operating company of the Port of Bluff, and is owned to 66.5% by the Southland Regional Council.^[12] A small port in comparison with New Zealand giants like Ports of Auckland or Port of Tauranga, it moves around 2.2 million tonnes of cargo each year, mostly New Zealand coastal reshipment. The Tiwai Point aluminium smelter and fossil fuel exploration activity in the Great South Basin may ensure the future relevance of the port.^[13] A recent (2008) weekly container ship service also lifted the volumes.^[14]

In July 2020, Rio Tinto announced closure of the aluminium smelter in August 2021,^[15][16] after which discussions were initiated on how to utilise the energy generated in Manapouri.^[17]

Bluff Harbour is the terminus for the twice-daily catamaran ferry to Stewart Island / Rakiura, 60 kilometres (37 mi) south across Foveaux Strait. It is the main gateway for New Zealand ships heading down to the Antarctic. The harbour is home to the Foveaux Strait oyster fleet. Bluff oysters are renowned for their succulence and flavour, and are considered a delicacy nationwide, with Bluff holding an annual oyster festival.^[18] The oyster quota was severely reduced during the 1990s due to the effects of the toxic protozoan parasite Bonamia exitiosa upon the oyster beds.^[19]

The Bluff Branch (formerly the Invercargill-Bluff Railway)) was the first railway line in Otago and Southland.^[20]

Te Rau Aroha marae is located at Bluff. It is a marae (meeting ground) for the Awarua Rūnanga branch of Ngāi Tahu, and includes the Tahu Potiki wharenui.^[21][22]

The town previously included the Paua House, created by Fred and Myrtle Flutey. This was an ordinary bungalow transformed by having the outside walls totally covered in pāua shells. The interior was also extensively decorated with paua and there is an extensive collection of (often kitsch) paua-decorated ornaments, utensils and trinkets.

The house became a museum after the death of the owners, but was sold and in March 2007 the exhibits removed to Christchurch. It has been on permanent display at the Canterbury Museum since July 2008.^[23]

The Bluff Maritime Museum contains an extensive collection of models, boats, artefacts, displays, a working triple expansion engine and a full sized oystering boat, the Monica.

Bluff School is a state full primary school serving years 1 to 8^[24] with a roll of 106 students as of February 2024.^[25] The school opened in 1867.^[26]

St Teresa's School is a state-integrated Catholic school serving years 1 to 8^[27] with a roll of 11 students. It has been operating since at least 1901.^[28]

• Hannah Ward Barron (1829–1898), successful businesswoman and hotel proprietor  
• Thomas Francis Doyle (1893–1968), member of the New Zealand Legislative Council
• Sir Joseph George Ward (1856–1930), Mayor of Campbelltown, Chair Bluff Harbour Board, founder J.G.Ward and Co, MP for Awarua 1887–1919 and for Invercargill 1925–1930, Prime Minister of New Zealand 1906–1912 and 1928–30.
• Dorothy May De Lany (1908–1970), first woman president of a trade union in New Zealand^[29]

• Ocean Beach (Bluff Harbour)