archipelago, northeastern Russia, lying north of eastern Siberia in the Arctic Ocean and dividing the Laptev Sea to the west from the East Siberian Sea to the east. Dmitry Laptev Strait separates the New Siberian Islands from the Siberian mainland. The archipelago is administratively part of Sakha (Yakutiya). The area of the islands is about 14,500 square miles (38,000 square km).

The New Siberian Islands consist of three groups: to the south the Lyakhovskye Islands, separated by Sannikova Strait from the New Siberian Islands proper, and to the northeast the small De Long Islands. The New Siberian Islands proper consist of the large islands of Novaya Sibir, Belkovsky, Kotelny, and Faddeyevsky. Between the last two lies Bunge Island, a low sandy plain occasionally inundated by the sea.

The New Siberian Islands do not rise above 1,227 feet (374 metres). The climate is severe and typically Arctic, with snow covering the ground for more than nine months of the year. The vegetation is poor tundra, even bushes being absent, and there is much swamp and barren sand. Fauna include the Arctic fox, northern deer, and lemming, with an abundant birdlife in summer.