Mount Erebus is the second-highest volcano in Antarctica (after Mount Sidley) and the southernmost active volcano on Earth. It is the sixth-highest ultra mountain on an island. With a summit elevation of 3,794 metres (12,448 ft), it is located on Ross Island, which is also home to three inactive volcanoes, Mount Terror, Mount Bird, and Mount Terra Nova.

The volcano has been active since about 1.3 million years ago and is the site of the Mount Erebus Volcano Observatory run by the New Mexico Institute of Mining and Technology.

Mount Erebus is currently the most active volcano in Antarctica and is the current eruptive zone of the Erebus hotspot. The summit contains a persistent convecting phonolitic lava lake, one of five long-lasting lava lakes on Earth.

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