Mount Sidley is the highest dormant volcano in Antarctica, and a member of the Volcanic Seven Summits (the highest volcanoes on each of the seven continents) with a summit elevation of 4,181–4,285 metres (13,717–14,058 ft). It is a massive, mainly snow-covered shield volcano, and the highest of the five volcanoes that comprise the Executive Committee Range of Marie Byrd Land. The feature is marked by a 5-kilometre-wide (3.1 mi) caldera on the southern side and stands northeast of Mount Waesche in the southern part of the range.

