Which desert is the largest desert in the world, including polar deserts?

The Antarctic Desert is the world’s largest desert when polar deserts are included.

Deserts are defined primarily by very low precipitation, not by heat. Antarctica receives little precipitation across its vast ice-covered interior, so it qualifies as a cold or polar desert even though most of its surface is frozen. Its immense ice sheet also makes the continent appear very different from the sandy deserts most people picture.

The Antarctic Desert covers roughly 13.8 million square kilometres if the continent’s desert classification is used, making it larger than the Arctic Desert and the Sahara. About 98% of Antarctica is covered by thick continental ice, while the remainder is exposed rock and other ice-free terrain. The McMurdo Dry Valleys are among its most striking examples of extreme aridity.

The common mistake is answering the Sahara. The Sahara is the largest hot desert, but it is smaller than both major polar deserts. The Arctic Desert is the second-largest overall, while the Gobi is a large cold winter desert rather than a polar desert. Thus, the wording “including polar deserts” points directly to Antarctica.