New Ireland, island of the Bismarck Archipelago, Papua New Guinea, southwestern Pacific Ocean. The island, lying just north of New Britain, from which it is separated by St. George’s Channel, has an area of 3,340 square miles (8,651 square km). It stretches for about 220 miles (350 km) from northwest to southeast but is very narrow, with the southeastern portion only 30 miles (48 km) wide and the 150-mile (241-km) northwestern arm no broader than 15 miles (24 km) and as narrow as 5 miles (8 km). It is generally rugged, especially in the south, where the Rossel Mountains rise to more than 7,050 feet (2,150 metres), and in the north, where the Schleinitz Range reaches 4,859 feet (1,481 metres). Limestone highlands occupy much of the northwest, with the Lelet Plateau averaging about 2,000 feet (610 metres) in elevation. Neighbouring islands to the east, Lihir and Ambitle, show solfataric and hot-spring activity, but there are no active volcanoes. There is a fringe of coastal plain leached by centuries of bush burning, and there are few good harbours.
Rock shelters near Namatanai, on the northeast coast, suggest that human habitation on the island dates back some 30,000 years, and there is evidence of trade as early as 12,000 years ago. New Ireland was sighted in 1616 by the Dutch navigator Jakob Le Maire, who believed it was part of a landmass including New Britain and New Guinea. This theory was disproved when British explorer Philip Carteret found St. George’s Channel in 1767 and named the island Nova Hibernia (New Ireland). An unsuccessful settlement attempt was made in 1880. Annexed by Germany in 1884, it was renamed New Mecklenburg. After World War I the island was mandated to Australia. During World War II it was occupied by the Japanese (1942), and after the war it became part of the UN Trust Territory of New Guinea, administered by Australia. When Papua New Guinea achieved independence in 1975, it became part of that country.
Commercial development is dominated by copra production, particularly on the east coast of New Ireland. Cocoa, rubber, and oil palms are also cultivated, and the waters to the north are among the Pacific’s richest for the harvest of skipjack tuna. In 1982 a major gold deposit was discovered in the caldera of Luise Volcano on Lihir Island, east of New Ireland, and mining began in 1997. At the time of its discovery the deposit was one of the world’s largest, and it yielded some 600,000 ounces (17,000 kg) of gold annually in the early 21st century.
Most of New Ireland’s inhabitants live in the north. This section is administered from Kavieng, the chief port, which is linked by an east-coast road to Samo. The central part of the island is administered from Konos and the southern portion from Namatanai.