Biruni Island (Bulgarian: остров Бируни, romanized: ostrov Biruni, IPA:[ˈɔstrovbiˈruni]) is the rocky island off the north coast of Elephant Island in the South Shetland Islands, Antarctica 450 m long in southwest–northeast direction and 150 m wide, with a surface area of 3.59 ha. It is separated from Elephant Island by a passage narrowing to 70 m at points. The island was formed as a result of the retreat of Elephant Island's ice cap at the turn of the 21st century.
The feature is named after Abu Rayhan Biruni (973-1048), an Iranian scholar who proposed the use of triangulation to measure distances and position places; in association with other names in the area deriving from the early development or use of geodetic instruments and methods.
Antarctic Digital Database (ADD). Scale 1:250000 topographic map of Antarctica. Scientific Committee on Antarctic Research (SCAR). Since 1993, regularly upgraded and updated.