Labrador Sea is an arm of the North Atlantic Ocean between Labrador and Greenland. Water depths in the centre of Labrador Sea are around 3 km and it is flanked by continental shelves to the SW, NW and NE. It connects to the north with Baffin Bay through the Davis Strait.

The Labrador Sea probably formed by sea-floor spreading that started around 61 million years ago and stopped about 40 million years ago. There is an earlier history of basin formation on all margins.

During the ice age, the north American ice sheet repeatedly collapsed sending armadas of icebergs into Labrador Sea. Rocks that melted from the icebergs today form a layer of drop stones (glacial erratics) on the bottom of Labrador Sea.

One of the world's largest turbidite channels runs N-S in the middle of Labrador Sea. Turbidite avalanches run down this channel for many hundreds of kilometres, many of them ending in very deep water off New England.