Vatnajökull (Icelandic pronunciation: [ˈvaʰtnaˌjœːkʏtl̥]), also known as the Vatna Glacier, is the largest and most voluminous ice cap in Iceland, and one of the largest in area in Europe. It is the second largest glacier in area after Austfonna on Svalbard in Norway. It is located in the south-east of the island, covering more than 8 percent of the country.
The name Vatnajökull is derived from vatna, the genitive plural form of vatn which means "water" in Icelandic but is also used to refer to a lake, and jökull, the Icelandic for glacier.
With an area of 8,100 km², Vatnajökull is the largest ice cap in Europe by volume (3,100 km³) and the second-largest (after Austfonna on Nordaustlandet, Svalbard, Norway) in area (not counting the still larger Severny Island ice cap of Novaya Zemlya, Russia, which may be regarded as located in the extreme northeast of Europe). On 7 June 2008, it became a part of the Vatnajökull National Park.
The average thickness of the ice is 400 m (1,300 ft), with a maximum thickness of 1,000 m (3,300 ft). Iceland's highest peak, Hvannadalshnúkur (2,109.6 m (6,921 ft)), is located in the southern periphery of Vatnajökull, near Skaftafell National Park.