The meridian 9° 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 9th meridian west forms a great circle with the 171st meridian east.
Starting at the North Pole and heading south to the South Pole, the 9th meridian west passes through:
| Co-ordinates | Country, territory or sea | Notes |
|---|---|---|
| Arctic Ocean | ||
| Atlantic Ocean | ||
| Island of Jan Mayen | ||
| Atlantic Ocean | ||
| Passing just east of Galway at 53°16'48"N | ||
| Atlantic Ocean | ||
| Mainland and island of Sálvora | ||
| Atlantic Ocean | ||
| Passing just east of Lisbon (at) | ||
| Atlantic Ocean | Passing just west of Cape St. Vincent, (at) | |
| Western Sahara | Claimed by | |
| Atlantic Ocean | ||
| Southern Ocean | ||
| Antarctica | Queen Maud Land, claimed by | |