The meridian 51° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Greenland, the Atlantic Ocean, South America, the Southern Ocean, and Antarctica to the South Pole. The 51st meridian west forms a great circle with the 129th meridian east.

From Pole to Pole

Starting at the North Pole and heading south to the South Pole, the 51st meridian west passes through: ! scope="col" width="120" | Co-ordinates ! scope="col" | Country, territory or sea ! scope="col" | Notes ! scope="row" style="background:#b0e0e6;" | Arctic Ocean ! scope="row" style="background:#b0e0e6;" | Lincoln Sea ! scope="row" | 🇬🇱 ! scope="row" style="background:#b0e0e6;" | Sherard Osborn Fjord ! scope="row" | 🇬🇱 ! scope="row" style="background:#b0e0e6;" | Disko Bay ! scope="row" | 🇬🇱 ! scope="row" style="background:#b0e0e6;" | Atlantic Ocean ! scope="row" | 🇧🇷 ! scope="row" style="background:#b0e0e6;" | Atlantic Ocean ! scope="row" style="background:#b0e0e6;" | Southern Ocean ! scope="row" | Antarctica