The meridian 40° east of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Europe, Asia, Africa, the Indian Ocean, the Southern Ocean, and Antarctica to the South Pole. The meridian is used in some contexts to delineate Europe or what is associated with the continent of Europe as an easternmost limit, e.g. to qualify for membership of the European Broadcasting Union. The 40th meridian east forms a great circle with the 140th meridian west.

From Pole to Pole

Starting at the North Pole and heading south to the South Pole, the 40th meridian east 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;" | Barents Sea ! scope="row" | 🇷🇺 ! scope="row" style="background:#b0e0e6;" | White Sea ! scope="row" | 🇷🇺 ! scope="row" style="background:#b0e0e6;" | White Sea ! scope="row" | 🇷🇺 ! scope="row" | 🇺🇦 ! scope="row" | 🇷🇺 ! scope="row" | 🇺🇦 ! scope="row" | 🇷🇺 ! scope="row" | 🇺🇦 ! scope="row" | 🇷🇺 ! scope="row" style="background:#b0e0e6;" | Black Sea ! scope="row" | 🇹🇷 ! scope="row" | 🇸🇾 ! scope="row" | 🇮🇶 ! scope="row" | 🇸🇦 ! scope="row" style="background:#b0e0e6;" | Red Sea ! scope="row" | 🇪🇷 ! scope="row" | 🇪🇹 ! scope="row" | 🇰🇪 ! scope="row" style="background:#b0e0e6;" | Indian Ocean ! scope="row" | 🇹🇿 ! scope="row" | 🇲🇿 ! scope="row" style="background:#b0e0e6;" | Indian Ocean ! scope="row" style="background:#b0e0e6;" | Southern Ocean ! scope="row" | Antarctica