叙尔特塞（冰岛语：Surtsey）是冰岛外海的一座火山岛，也是冰岛的最南端。它是因海面下130公尺火山爆发而形成，于1963年11月14日突出海面。火山喷发一直持续到1967年6月5日，岛的面积也达到最大值2.7平方公里。之后，由于风和波浪的侵蚀，导致岛逐渐变小，到了2002年，其面积为1.4平方公里。

岛名来源于北欧神话中的巨人史尔特尔（Surtr），是一位火神，火山学家在火山喷发期间集中研究了这座岛屿，之后植物学家和动物学家研究生命如何在这座原本光秃秃的岛上形成。叙尔特塞属于大西洋洋中脊板块韦斯特曼纳群岛海底火山群。

Surtsey ("Surtr's island" in Icelandic, pronounced ˈsʏr̥tsei) is a volcanic island located in the Vestmannaeyjar archipelago off the southern coast of Iceland. At 63°18′11″N 20°36′18″W / 63.303°N 20.605°W / 63.303; -20.605, Surtsey is the southernmost point of Iceland. It was formed in a volcanic eruption which began 130 metres (426 ft) below sea level, and reached the surface on 14 November 1963. The eruption lasted until 5 June 1967, when the island reached its maximum size of 2.7 km (1.0 sq mi). Since then, wave erosion has caused the island to steadily diminish in size: as of 2002, its surface area was 1.4 km (0.54 sq mi). The most recent survey (2007) shows the island's maximum elevation at 155 m (509 ft) above sea level.