The meridian 20° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Greenland, Iceland, the Atlantic Ocean, the Southern Ocean, and Antarctica to the South Pole. The 20th meridian west forms a great circle with the 160th meridian east.
In Antarctica, the meridian defines the border between the British Antarctic Territory and Queen Maud Land. Between the 5th parallel north and the 60th parallel south it forms the eastern boundary of the Latin American Nuclear-Weapon-Free Zone.
|Co-ordinates||Country, territory or sea||Notes|
|Greenland||Gamma Island and Germania Land|
|Greenland||Mainland, Kuhn Island, and the mainland again|
|Atlantic Ocean||Greenland Sea|
|Antarctica||Border between the Antarctic territorial claims of the United Kingdom and Norway|