The meridian 1° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, the Atlantic Ocean, Europe, Africa, the Southern Ocean, and Antarctica to the South Pole. The 1st meridian west forms a great circle with the 179th meridian east. It is the most populous meridian west of Greenwich, being home to between 41.2 million and 44.9 million people as of 2019.

From pole to pole

Starting at the North Pole and heading south to the South Pole, the 1st meridian west passes through: ! scope="col" width="125" | Co-ordinates ! scope="col" | Country, territory or sea ! scope="col" | Notes ! scope="row" style="background:#b0e0e6;" | Arctic Ocean ! scope="row" style="background:#b0e0e6;" | Atlantic Ocean ! scope="row" | ! scope="row" style="background:#b0e0e6;" | North Sea ! scope="row" | ! scope="row" style="background:#b0e0e6;" | North Sea ! scope="row" | ! scope="row" style="background:#b0e0e6;" | English Channel ! scope="row" | 🇫🇷 ! scope="row" | 🇪🇸 ! scope="row" style="background:#b0e0e6;" | Mediterranean Sea ! scope="row" | 🇩🇿 ! scope="row" | 🇲🇦 ! scope="row" | 🇩🇿 ! scope="row" | undefined ! scope="row" | 🇧🇫 ! scope="row" | 🇬🇭 ! scope="row" style="background:#b0e0e6;" | Atlantic Ocean ! scope="row" style="background:#b0e0e6;" | Southern Ocean ! scope="row" | Antarctica