The glaciers and ice caps of Iceland cover 11.1% of the land area of the country (about 11,400 km² out of the total area of 103,125 km²) and have a considerable impact on its landscape and meteorology. An ice cap is a mass of glacial ice that covers less than 50,000 km² of land area covering a highland area and they feed outlet glaciers. Glaciers are also contributing to the Icelandic economy, with tourists flocking to the country to see glaciers on snowmobiles and on glacier hiking tours.
Many Icelandic ice caps and glaciers lie above volcanoes, such as Grímsvötn and Bárðarbunga, which lie under the largest ice cap, Vatnajökull. The caldera of Grímsvötn is 100 km² in area, and Bárðarbunga is 60 km².
When volcanic activity occurs under the glacier, the resulting meltwater can lead to a sudden glacial lake outburst flood, known in Icelandic as jökulhlaup, but jökulhlaups are most often caused by accumulation of meltwater due to geothermal activity underneath the glacier. Such jökulhlaups have occasionally triggered volcanic eruptions through the sudden release of pressure.
Iceland is losing ice due to climate change. Okjökull glacier in Borgarfjörður, West Iceland, has lost its glacier title and is now simply known as “Ok”. In order to fit the criteria glaciers need to be thick enough to sink and move under their own weight, which Ok is not. Ok is the first Icelandic glacier to lose its title.
The Icelandic word for glacier is .
These 13 largest glaciers have an aggregate area of 11,181 km² (out of about 11,400 km² for all glaciers of Iceland).