What is the largest non-polar desert in the world?

The largest non-polar desert in the world is the Sahara. Spanning roughly 9.2 million square kilometres across North Africa, it is also the world's largest hot desert and the third-largest desert overall, after Antarctica and the Arctic.

The Sahara stretches from the Atlantic Ocean to the Red Sea and from the Mediterranean coast toward the Sahel. It crosses or touches Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Sudan, Tunisia and Western Sahara. Its landscapes include sand seas, rocky plateaus, gravel plains, dry valleys and salt flats—not just dunes.

A common mix-up is confusing the Sahara with the world's largest desert of any kind. Antarctica and the Arctic qualify as deserts because they receive very little precipitation, even though they are polar regions. The Sahara's name comes from the Arabic ṣaḥrāʾ, meaning “desert.” Its climate is shaped partly by descending, dry air in the subtropical high-pressure belt.