Vestmannaeyjar ("Westman Islands") is a town and archipelago off the south coast of Iceland.
The largest island, Heimaey, has a population of 4,135. The other islands are uninhabited, though six have single hunting cabins. Vestmannaeyjar came to international attention in 1973 with the eruption of Eldfell volcano, which destroyed many buildings, and forced a months-long evacuation of the entire population to mainland Iceland.
The Vestmannaeyjar archipelago is considered young in geological terms. The islands lie in the Southern Icelandic Volcanic Zone and have been formed by eruptions over the past 10,000–12,000 years. The volcanic system consists of 70–80 volcanoes both above and below the sea.

There are 15 islands, and about 30 rock stacks and skerries. All the islands have been built up in submarine eruptions and consist of alternating layers of palagonite tuff and lava. The oldest geological formations are in the northern part of Heimaey ("Home Island"), the largest island and the only one of the group that is inhabited. Basalt columns can be seen in many places, and the sea has eroded the soft rock of the shoreline and scooped out many picturesque coves and grottos, which are one of the special features of the islands.

A submarine eruption took place southeast of Hellisey in 1896. The next eruption began on 14 November 1963. It lasted about four years – one of the longest in Icelandic history – and gave birth to Surtsey, the 15th island in the group. In the eruption of 1973 that lasted for 155 days, Heimaey grew by about 2.1 square kilometres (0.81 sq mi). The Westman Islands group is about 38 kilometres (24 mi) long and 29 kilometres (18 mi) broad, the closest point lying about 8 kilometres (5.0 mi) from the mainland.