Scoresby Sund is an inlet system of the Greenland Sea on the eastern coast of Greenland. It has a tree-like structure, with a main body approximately 110 km long that branches into a system of fjords covering an area of about 38,000 km² . The longest of these extends 340–350 km in from the coastline. The depth is 400–600 m in the main body, but this increases to up to 1,450 m (4,760 ft) in the fjords. It is the largest and longest fjord system in the World.
The name honors the English explorer William Scoresby, who in 1822 mapped the fjord area in great detail. Numerous islands are present. The largest, Milne Land, has an area of 3,913 km² and is located in the middle of the inlet. On the northern side of the mouth stands Ittoqqortoormiit, the only permanent settlement in the region, with a population of 469 (in 2010).