Humboldt Glacier, Tidewater glacier in northwestern Greenland.

Humboldt Glacier is a tidewater glacier in the Qaanaaq district of Avannaata Municipality, northwestern Greenland, lying between Inglefield Land to the southwest and Washington Land to the northeast. Its front is 110 km wide, the widest of any tidewater glacier in the Northern Hemisphere, and it fringes the coast of Peabody Bay from north to south. The McGary Islands lie off its southern end, where the bay opens into the Kane Basin.

The glacier was named during the Second Grinnell Expedition of 1853–1855 led by Elisha Kent Kane, who honoured Alexander von Humboldt. Kane charted the ice front along the Kane Basin rather than claiming its discovery. Between 1972 and 2021 the glacier lost about 161 billion tonnes of ice and retreated 13 km.

Greenlandic gives the glacier the name Sermersuaq, meaning "the great ice", used in the Qaanaaq district of Avannaata Kommunia. The name appears in the Danish form Humboldt Gletscher and in the German Humboldt-Gletscher, while English sources keep Humboldt Glacier after Alexander von Humboldt.

Reaching this location requires special permissions and experienced guides, as access is extremely limited and challenging. Visits are only practical during warmer months when regional travel becomes marginally more feasible.

This glacier continuously produces enormous icebergs that drift through adjacent waterways into distant southern seas. These massive ice chunks travel thousands of kilometers and impact maritime navigation across a vast region.