The Denmark Strait or Greenland Strait (Danish: Danmarksstrædet, Icelandic: Grænlandssund, the latter meaning Greenland Sound) is an oceanic strait between Greenland (to its northwest) and Iceland (to its southeast). The Norwegian island of Jan Mayen lies northeast of the strait.

It connects the Greenland Sea, an extension of the Arctic Ocean, to the Irminger Sea, a part of the Atlantic Ocean, and is 300 miles (480 km) long and 180 miles (290 km) miles wide at its narrowest, from Straumnes, the northwestern headland of the north west Icelandic peninsula of Hornstrandir, und Cape Tupinier on Blosseville Coast in East Greenland). The official IHO delineation between the Arctic and the North Atlantic Oceans, however, runs from Straumness to Cape Nansen, which is 132 km (82 miles) southwest of Cape Tunipier. From Straumnes to Cape Nansen the distance is 336 km (209 miles).

The narrow depth, where the Greenland-Iceland Rise runs on the bottom of the sea, is 625 feet (191 m). The cold East Greenland Current passes through the strait and carries icebergs south into the north Atlantic Ocean. It hosts important fishing grounds.

The Kingdom of Denmark (Danish: Kongeriget Danmark, pronounced [ˈkɔŋəʁiːəð ˈdanmɑɡ̊] ( listen)) is a constitutional monarchy and sovereign state consisting the country of Denmark in northern Europe and two autonomous constituent countries, the Faroe Islands in the North Atlantic and Greenland in North America. The kingdom is a unitary state with some power being devolved from Denmark proper to Greenland and the Faroe Islands; this polity is referred to as the Danish Realm. Denmark proper is the hegemonial area, where judicial, executive, and legislative power resides. The Faroe Islands are defined to be a community of people within the kingdom, and the Greenlandic people are defined as a separate people with the right to self-determination.

Denmark is the southernmost of the Nordic countries, located southwest of Sweden and south of Norway, and bordered to the south by Germany. The country consists of a large peninsula, Jutland and many islands, most notably Zealand, Funen, Lolland, Falster and Bornholm, as well as hundreds of minor islands often referred to as the Danish Archipelago.