The area on which the city was founded has been inhabited by the Motu-Koitabu people for centuries. It was first sighted by a European in 1873 by Captain John Moresby. It was named in honour of his father Admiral Sir Fairfax Moresby.
The Motuan people of the area now known as Port Moresby traded their pots for sago, other food and canoe logs, sailing from Hanuabada and other villages built on stilts above the waters of the bay. They also intermarried with the Gulf people and created strong family and trade links.
The Hiri expeditions were large-scale. As many as 20 multi-hulled canoes or lakatoi, crewed by some 600 men, carried about 20,000 clay pots on each journey. To the Motuans, the Hiri was not only an economic enterprise but they also confirmed their identity as a tribe because of the long and dangerous voyages. These voyages are commemorated in modern times by the annual Hiri Moale Festival held at Ela Beach in September.
The area was already an important trade centre by the time Captain John Moresby of HMS Basilisk first identified the area of the site later to become known as Port Moresby. The Englishman had just ventured through the Coral Sea at the eastern end of New Guinea and upon encountering three previously unknown islands landed there. At 10 o’clock in the morning of 20 February, 1873, he claimed the land for Britain and named it after his father, Admiral Sir Fairfax Moresby. He called the inner reach "Fairfax Harbour" and the other Port Moresby.
Actual European settlement of the site did not occur until a decade later when the southeastern part of New Guinea island was annexed to British Empire. British New Guinea was passed to the newly established Commonwealth of Australia in 1906, and became known as Papua. From then until 1941 Port Moresby grew slowly. The main growth was on the peninsula, where port facilities and other services were gradually improved. Electricity was introduced in 1925 and piped water supply was provided in 1941.
During World War II, many Papuan men were enlisted, both as soldiers in the Papua Infantry Battalion, and as carriers for supply support to Allied armies. Many other Papuan residents of Port Moresby either returned to their villages or were evacuated to camps when the threat of Japanese invasion loomed. The city was home to an important Allied base and thousands of troops were stationed in the area as the last allied bastion on the island and last defense between the Japanese onslaught and Australia. This key role resulted in its becoming the objective of a Japanese invasion fleet in May 1942 that was stopped by the Battle of Coral Sea. During this period Port Moresby, especially its "villages" naturally fell into disrepair and after the war the whole town had to be rebuilt.
In 1945, the Territory of Papua and New Guinea was formed when Papua and the former German New Guinea, which had been administered by Australia since 1918, were amalgamated under a single Australian Administration. Port Moresby was officially designated the capital of the new "combined" territory and a focal point for the expansion of public services.
Unfortunately, several of these government buildings have now been abandoned due to long-term neglect. Chief amongst these are Marea Haus (known to most locals as the "Pineapple Building") and the Central Government Offices. Nearby buildings such as Morauta Haus and Vulupindi Haus are now starting to show significant signs of decay due to a lack of maintenance, including crumbling fire stairs, grimy restrooms and elevators that are always out of service.
The population of the Port Moresby area has expanded rapidly since independence. In 1980 the census registered 120,000; by 1990, this had increased to 195,000.
The city is often covered by a smoke haze that is created by the numerous small fires lit beside the road or in the bush by its inhabitants. These are left to burn out without intervention by the local fire department.
In 2004, Port Moresby was ranked the worst capital city in the world to live in the Economist Intelligence Unit's ranking of 130 of the world's capital cities . High levels of rape, robbery and murder and large areas of the city controlled by gangs of thugs, known locally as "rascals" (Tok Pisin raskol), were cited. According to a 2004 article in the Guardian newspaper, unemployment rates are estimated to be between 60 and 90% and murder rates three times that of Moscow and 23 times the rate in London.
Port Moresby refers to both the urbanised area of the National Capital District and more specifically to the main business area, known locally as "Town". Other neighbourhoods of Port Moresby include: Koki, with its popular fresh produce market, Newtown, Konedobu, Kaevaga, Badili, Gabutu, Kila, Matirogo, Three Mile, Kaugere, Sabama, Korobosea, Four Mile, Hohola, Hohola North, Boroko, a major shopping area, Gordon, Gordon North, Erima, Saraga, Waigani, Morata and Gerehu. There are also villages like Hanuabada, the biggest village in Papua New Guinea.
Port Moresby is served by Jacksons International Airport, which is the biggest international airport and Air Force base in the country. Air Niugini and Airlines PNG both conduct regular domestic and international routes from this airport.
As the national highways system is discontinuous, there are many internal flights to other towns which cannot be reached by minibuses, known as PMVs locally, e.g. Madang.