King Oscar Fjord is a fjord in East Greenland, marking the northern border of the peninsula Scoresby Land. It is a major fjord, 10–25 km wide, bounded by Traill Island and Geographical Society Island. In the inner and northern end of the fjord lies Ella Island. Lyell Land and Stauning's Alps lie to the Southwest. It was named by A.G. Nathorst on his 1899 expedition as Konung Oscars Fjord for Oscar II, King of Sweden from 1872–1907.