The meridian 43° 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 43rd meridian west forms a great circle with the 137th meridian east.
Starting at the North Pole and heading south to the South Pole, the 43rd meridian west passes through:
| Co-ordinates | Country, territory or sea | Notes |
|---|---|---|
| Arctic Ocean | ||
| Lincoln Sea | ||
| Nansen Land J.P. Koch Fjord — Freuchen Land — Paatusoq — | ||
| Atlantic Ocean | ||
| Maranhão Piauí — Maranhão — Piauí — Bahia — Minas Gerais — Rio de Janeiro (state) —, passing just east of the city of Rio de Janeiro (at) | ||
| Atlantic Ocean | ||
| Southern Ocean | ||
| Antarctica | Claimed by both (Argentine Antarctica) and (British Antarctic Territory) | |