It is situated on a peninsula in the south of New Caledonia's main island, Grande Terre, and is home to the majority of the island's European, Polynesian (Wallisians, Futunians, Tahitians), Indonesian, and Vietnamese populations, as well as many Melanesians, Ni-Vanuatu and Kanaks that work in one of the South Pacific's most industrialised cities. The city lies on a protected deepwater harbour which serves as the chief port for New Caledonia.

At the August 2014 census, there were 179,509 inhabitants in the metropolitan area of Greater Nouméa (French: agglomération du Grand Nouméa), 99,926 of whom lived in the city (commune) of Nouméa proper. 66.8% of the population of New Caledonia live in Greater Nouméa, which covers the communes of Nouméa, Le Mont-Dore, Dumbéa and Païta.

The first European to establish a settlement in the vicinity was British trader James Paddon in 1851. Anxious to assert control of the island, the French established a settlement nearby three years later in 1854, moving from Balade in the north of the island. This settlement was initially called Port-de-France and was renamed Nouméa in 1866. The area served first as a penal colony, later as a centre for the exploitation of the nickel and gold that was mined nearby.

From 1904 to 1940 Nouméa was linked to Dumbéa and Païta by the Nouméa-Païta railway, the only railway line that ever existed in New Caledonia.

During World War II, Nouméa served as the headquarters of the United States military in the South Pacific. The five-sided U.S. military headquarters complex was adopted after the war as the base for a new regional intergovernmental development organisation: the South Pacific Commission, later known as the Secretariat of the Pacific Community.

The city maintains much of New Caledonia's unique mix of French and old Melanesian culture. Even today the U.S. wartime military influence lingers, both with the warmth that many New Caledonian people feel towards the United States after experiencing the relative friendliness of American soldiers and also with the names of several of the quarters in Nouméa. Districts such as "Receiving" and "Robinson", or even "Motor Pool", strike the anglophone ear strangely, until the historical context becomes clear.

The city is situated on an irregular, hilly peninsula near the southeast end of New Caledonia, which is in the south-west Pacific Ocean.

Rivière-Salée

6e km, 7e km, Normandie, and Tina

Ducos peninsula:

Ducos, Ducos industriel, Kaméré, Koumourou, Logicoop, Numbo, Tindu

4e Km, Aérodrome, Haut Magenta, Magenta, Ouémo, and Portes de fer

Faubourg Blanchot and Vallée des Colons

Doniambo, Montagne coupée, Montravel, and Vallée du tir

Artillerie Nord, Centre Ville, Nouville, Quartier Latin, Vallée du Génie

Anse Vata, Artillerie Sud, Baie des Citrons, Motor Pool, N'géa, Orphelinat, Receiving, Trianon, and Val Plaisance

The Greater Nouméa urban area (French: agglomération du Grand Nouméa) had a total population of 179,509 inhabitants at the August 2014 census, 99,926 of whom lived in the commune of Nouméa proper.

Nouméa (99,926 inh.)

Dumbéa (31,812 inh.), to the north-west of Nouméa

Le Mont-Dore (27,155 inh.), to the north-east of Nouméa

Païta (20,616 inh.), a suburb to the west of Dumbéa and the site of La Tontouta International Airport

The places of birth of the 163,723 residents in the Greater Nouméa urban area at the 2009 census were the following:

66.9% were born in New Caledonia

20.2% in Metropolitan France and its overseas departments

7.1% in foreign countries (notably Indonesia, Vanuatu, Vietnam, and Algeria where many of New Caledonia's Pied-Noir residents originated)

4.1% in Wallis and Futuna

1.7% in French Polynesia

At the 2009 census, 98.7% of the population in the Greater Nouméa urban area whose age was 15 years old and older reported that they could speak French. 97.1% reported that they could also read and write it. Only 1.3% of the population whose age was 15 years old and older had no knowledge of French.

At the same census, 20.8% of the population in the Greater Nouméa urban area whose age was 15 years old and older reported that they could speak at least one of the Kanak languages. 4.3% reported that they could understand a Kanak language but not speak it. 74.9% of the population whose age was 15 years old and older had no knowledge of any Kanak language.

Nouméa features a tropical wet and dry climate with hot summers and warm winters. Temperatures are warmer in the months of January, February and March with average highs hovering around 30 degrees Celsius and cooler during the months of July and August where average high temperatures are around 23 degrees Celsius. The capital’s dry season months are September and October. The rest of the year is noticeably wetter. Nouméa on average receives roughly 1,100 mm (43 in) of precipitation annually.