Eyjafjallajökull — translated as "Eyja-fjalla glacier" or "island-mountain glacier" — is one of the smaller glaciers of Iceland, situated to the north of Skógar and to the west of Mýrdalsjökull. The icecap of the glacier covers a volcano with a summit elevation of 1,666 metres (5,466 ft). The volcano has erupted relatively frequently since the last glacial period, most recently from 1821 to 1823 and again in 2010.

The volcano, which has a crater 3–4 kilometres (1.9–2.5 mi) in diameter, erupted in 920, 1612 and again from 1821 to 1823 when it caused a glacial lake outburst flood. It has erupted twice in 2010 — on 20 March and 14 April. The March event forced a brief evacuation of around 500 local people, but the April eruption was ten to twenty times more powerful and is causing substantial disruption to air traffic across Northern Europe.