The meridian 99° 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 99th meridian west forms a great circle with the 81st meridian east.

From Pole to Pole

Starting at the North Pole and heading south to the South Pole, the 99th meridian west passes through: ! scope="col" width="120" | Co-ordinates ! scope="col" | Country, territory or sea ! scope="col" | Notes ! scope="row" style="background:#b0e0e6;" | Arctic Ocean ! scope="row" | 🇨🇦 ! scope="row" style="background:#b0e0e6;" | Peary Channel ! scope="row" style="background:#b0e0e6;" | Hassel Sound ! scope="row" | 🇨🇦 ! scope="row" style="background:#b0e0e6;" | Unnamed waterbody ! scope="row" | 🇨🇦 ! scope="row" style="background:#b0e0e6;" | Parry Channel ! scope="row" | 🇨🇦 ! scope="row" style="background:#b0e0e6;" | Larsen Sound ! scope="row" style="background:#b0e0e6;" | Victoria Strait ! scope="row" | 🇨🇦 ! scope="row" style="background:#b0e0e6;" | Queen Maud Gulf ! scope="row" | 🇨🇦 ! scope="row" style="background:#b0e0e6;" | Queen Maud Gulf ! scope="row" | 🇨🇦 ! scope="row" | 🇺🇸 ! scope="row" | 🇲🇽 ! scope="row" style="background:#b0e0e6;" | Pacific Ocean ! scope="row" style="background:#b0e0e6;" | Southern Ocean ! scope="row" | Antarctica