Bluff (Pop:1850) is a town and seaport in the Southland region, on the southern coast of the South Island of New Zealand. It is the southern-most town in New Zealand and despite Slope Point being further to the south, is colloquially used to refer to the southern extremity of the country (particularly in such phrases as "from Cape Reinga to The Bluff").

The Bluff area, while itself not settled by Māori, was one of the earliest areas of New Zealand where a European presence became established. This is the foundation for the claim that this makes Bluff the oldest permanent European settlement in the country. However the missionary settlement at Kerikeri was both earlier and larger and the town is now larger than that of Bluff.

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.

Bluff is dominated by Bluff Hill, an extinct volcanic cone, which provides some shelter from the prevailing westerly winds. There is a world-class walk 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

Among the attractions of the town was the Paua house, created by the (now deceased) Fred and Myrtle Flutey. This house was an ordinary bungalow transformed by having the outside walls totally covered in paua shells. The interior was also extensively decorated with paua and there is an extensive collection of 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 the Canterbury Museum in Christchurch.

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 harbour is also the terminus for the twice-daily catamaran ferry to Stewart Island/Rakiura, 60 km south across Foveaux Strait.

There are no passenger train or rail services from Bluff to Invercargill, Queenstown, Te Anau, Dunedin or Christchurch