The meridian 108° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole.
The 108th meridian west forms a great circle with the 72nd meridian east.
Starting at the North Pole and heading south to the South Pole, the 108th meridian west passes through:
| Co-ordinates | Country, territory or sea | Notes |
|---|---|---|
| Arctic Ocean | ||
| Byam Martin Channel | ||
| Nunavut — Melville Island | ||
| Parry Channel | Viscount Melville Sound | |
| Nunavut — Kilian Island | ||
| Parry Channel | Viscount Melville Sound | |
| Nunavut — Victoria Island | ||
| Hadley Bay | ||
| Nunavut — Victoria Island | ||
| Dease Strait | ||
| Nunavut — the Kent Peninsula (mainland) | ||
| Melville Sound | ||
| Nunavut — the Barry Islands, the Banks Peninsula (mainland), the Young Islands, and the mainland Northwest Territories — from Saskatchewan — from, passing through Lake Athabasca | ||
| Montana Wyoming — from Colorado — from New Mexico — from | ||
| Chihuahua Sinaloa — from | ||
| Pacific Ocean | ||
| Southern Ocean | ||
| Antarctica | Unclaimed territory | |