Central Wellington is located on parts of the western and southern sides of the harbour, and the suburban area of Lower Hutt is to the north and east.

[3] However, while Herd is attributed as the creator of the first charts describing Te Whanganui a Tara as "Port Nicholson" it is likely that Captain John Rodolphus Kent of the cutter Mermaid had entered the harbour in 1824, and named it after the harbourmaster, his superior officer.

[8][9] An alternative suggested etymology for the name Pōneke states that it derives from a shortening of the Māori phrase pō nekeneke, meaning "the journey into the night", in reference to the exodus of Te Āti Awa after they were displaced from the Wellington area by the first Europeans.

[14] Alternatively, it could have been named for the Lambton, a cutter commanded by Captain Barnett, who in 1826 had produced one of the earliest charts of the harbour.

He anchored a mile from Barrett Reef, and made some brief observations noting that it appeared to be a sheltered harbour.

[2] According to legend, the harbour of Te Whanganui-a-Tara was created by two taniwha (nature guardian spirits), Whātaitai (or Hataitai) and Ngake.

[22][23] Ngake could hear the waters of Raukawa Moana (Cook Strait) pounding to the south, and decided to escape the lake to get to it.

The shipping channel through the harbour entrance lies between Barrett Reef on the western side, and Pencarrow Head to the east.

Lambton Harbour is surrounded by the reclaimed land of Wellington's central business district and contains the majority of the city's port facilities.

Evans Bay lies between Mt Victoria and the Miramar Peninsula, and is below the flight path to low-lying Wellington Airport.

[28] At the northern end of the harbour lies the narrow triangular plain of the Hutt River, which largely follows the line of the earthquake fault to the north-east.

Then a violent earthquake known as Haowhenua (Māori for 'land swallower') uplifted the land so that the Te-Awa-a-Taia channel dried up and the island of Motu-Kairangi became joined to the mainland.

[33] In August 1868, the Arica earthquake in South America causes unusual changes in water levels in the harbour.

[36][37] The harbour basin contains massive quantities of gravel washed down from the Hutt River, in some places hundreds of metres deep.

The water level in Wellington Harbour was much lower 20,000 years ago, and the ancient Hutt River used to flow down a paleochannel to the east of Matiu / Somes Island as far as the present-day Miramar Peninsula.

Land plots in the early city were scarce, with little room for public buildings and parks, as well as inadequate dockside areas for shipping.

Reclamation progressively advanced into the harbour throughout the 19th and 20th centuries, providing room for public, commercial and industrial areas for the city.

[47] In the late nineteenth and early twentieth centuries, large octopuses would occasionally grab people at the water's edge.

[63] Rocky shores around the harbour support kelp forests, for example at Kau Bay, but rising sea temperatures may be affecting the health of these areas.

[66] Between 2018 and 2022, annual surveys were made of indigenous coastal birdlife along the coastlines of the south coast and the western side of Wellington Harbour.

[67] The surveys showed that stretches of the coastline "hardened" by reclamation or seawall construction have lower densities of birds and less diversity of species, probably due to the steepness of the shoreline and lack of intertidal foraging habitats.

[69] Water quality is affected by sediment, nutrients and pollutants from the whole catchment around the harbour, turbidity caused by rainfall and outflow from the Hutt River, and tides.

[69][70] The Ministry of Agriculture and Forestry and NIWA have carried out surveillance on non-indigenous marine species which may arrive in the harbour in water ballast or attached to hulls of ships.

[73] Volunteers from the group Ghost Diving organise regular harbour clean-ups, collecting tonnes of rubbish from the water around the inner-city waterfront and bringing attention to the problem of littering.

[74][75] Wellington Harbour is a significant port serving the lower North Island, with the Regional Council-owned company CentrePort recording around 14,000 commercial shipping movements each year.

[2] Te Ara Tupua is a cycling and walking path being built from Melling in the Hutt Valley to central Wellington.

Wharves were built for various purposes – moving fuel, primary products such as timber, wool and meat coming from the hinterland, other goods and passengers.

Many wharves have been repurposed in response to changing domestic and international conditions and requirements for maritime transport of passengers and cargo.

Wellington's south coast and harbour entrance are exposed to open sea, providing places to dive and fish.

Harbour cruises also travel regularly between the main Wellington waterfront, Matiu / Somes Island, Days Bay and Petone.