The Denmark Strait (Danish: Danmarksstrædet) or Greenland Strait (Icelandic: Grænlandssund, the latter meaning Greenland Sound) is an oceanic strait between Iceland (to its southeast) and Greenland (to its northwest). 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 stretches 300 miles (480 km) long and 180 miles (290 km) miles wide at its narrowest, from Straumnes the northwestern headland of the Westfjords peninsula of Hornstrandir and Cape Tupinier on Blosseville Coast in East Greenland). The official International Hydrographic Organization (IHO) delineation between the Arctic and the North Atlantic Oceans runs from Straumness to Cape Nansen, 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. It hosts important fisheries.
The world's largest underwater waterfall, flows down the Western side of the Denmark Strait, known as the Denmark Strait cataract.