Austfonna is an ice cap located on Nordaustlandet in the Svalbard archipelago in Norway. Covering an area of 7,800 km, it is Europe's third-largest glacier by area and volume, after the Severny Island ice cap of Novaya Zemlya, Russia, and Vatnajökull in Iceland. The combined area of Austfonna and the Vegafonna ice cap is 8,492 km.
Austfonna has a thickness of up to 560 metres (235 meters average thickness), and is 200 km in circumference. The ice dome reaches an elevation of 783 meters above sea level.