What is the largest desert on Earth overall?

The Antarctic Desert is the largest desert on Earth overall. Antarctica qualifies as a desert because it receives very little precipitation, despite being covered almost entirely by ice.

At about 14.2 million square kilometres, Antarctica is larger than the Sahara and includes the continent’s enormous polar ice sheet. Roughly 98% of the continent is covered by ice, while some exposed areas, such as the McMurdo Dry Valleys, are exceptionally arid and may receive almost no snowfall for long periods.

The usual mistake is assuming that a desert must be hot or sandy. Deserts are defined primarily by scarce precipitation, so polar deserts count. The Arctic Desert is also larger than many people expect, but it is smaller than the Antarctic Desert. The Sahara is the world’s largest hot desert, not the largest desert of any kind.