Kalahari Desert, a semiarid to arid region in southern Africa, mainly in Botswana, South Africa, and Namibia. Its area is about 120,000 square miles (310,000 km2). Annual rainfall varies greatly. The northeastern part of the Kalahari receives the most rain—up to 20 inches (500 mm) annually. Rainfall declines toward the southeast, where some areas receive virtually no rain. Summer daytime temperatures often reach more than 100° F. (38° C.).

The Kalahari is covered largely by drought-resistant grasses and acacia thornbush. Sand dunes are found in some areas. Animals such as gemsbok, wildebeest, and lions wander much of the Kalahari. National parks have been established in Botswana and South Africa to protect the wildlife. A small number of San (Bushmen), nomadic hunters and gatherers, inhabit the area.

The first Europeans to cross the Kalahari were the British explorers David Livingstone and William C. Oswell, in 1849.