The Malaspina Glacier in southeastern Alaska is the largest piedmont glacier this far south in North America. It is about 65 km (40 mi) wide and 45 km (28 mi) long, with an area of some 3,900 km² (1,500 sq mi). It is named after the Italian explorer Alessandro Malaspina (commissioned by Spain), who visited the region in 1791.
It forms where several valley glaciers, primarily the Seward Glacier and Agassiz Glacier, spill out from the Saint Elias Mountains onto the coastal plain facing the Gulf of Alaska between Icy Bay and Yakutat Bay. Although it fills the plain, nowhere does it actually reach the water and so does not qualify as a tidewater glacier.
The Malaspina is up to 600 meters thick in places, with a bottom estimated at up to 300 meters below sea level. There are two lakes on the margin of the glacier; Oily Lake at the foot of the Samovar Hills between the Agassiz and Seward glaciers, and Malaspina Lake at the southeast margin, close to Yakutat Bay.
Study of radar data and aerial photographs dating back to 1972 shows that the Malaspina-Seward system lost about 20 m (60 ft) of its thickness between 1980 and 2000; because the glacier is so large, that was sufficient to contribute 1/2 of one percent of the rise in the global sea level.
The glacier is protected within the boundaries of the Wrangell-St. Elias National Park and Preserve.
In October of 1969, the glacier became a National Natural Landmark.
The glacier is the namesake of the Alaska Marine Highway vessel the M/V Malaspina.