The Namib Desert is a desert in Namibia and southwest Angola which forms part of the Namib-Naukluft National Park one of Africa's largest. The name "Namib" is of Nama origin. The desert occupies an area of around 50 000 km², stretching about 1000 miles (1,600 km) along the Atlantic Ocean coast of Namibia, which is named after this desert.

Its east-west width varies from 30 to 100 miles (50-160 km). The Namib Desert also reaches into southwest Angola. It is one of 11 distinct physiographic provinces of the South African Platform physiographic division.

The area is considered one of the oldest desert in the world, having endured arid or semi-arid conditions for at least 55 million years after Atacama Desert. Its aridity is caused by the descent of dry air of the Hadley Cell, cooled by the cold Benguela current along the coast. It has less than 10 mm (0.4 inches) of rain annually and is almost completely barren.

A number of unusual species of plants and animals are found only in this desert. One of these is Welwitschia mirabilis, one of the most unusual species. Welwitschia is a shrub-like plant, but grows just two long, strap-shaped leaves continuously throughout its lifetime. These leaves may be several meters long, gnarled and twisted from the desert winds. The taproot of the plant develops into a flat, concave disc in age. Welwitschia is notable for its survival in the extremely arid conditions in the Namib, sometimes deriving moisture from the coastal sea fogs.

Although the desert is largely unpopulated and inaccessible, there are year-round settlements at Sesriem, close to the famous Sossusvlei and a huge group of sand dunes, which at up to 340 metres high are among the tallest sand dunes in the world. The complexity and regularity of dune patterns in its dune sea have attracted the attention of geologists for decades; however, they remain poorly understood.

The interaction between the water-laden air coming from the sea via southerly winds, some of the strongest of any coastal desert, and the dry air of the desert causes immense fogs and strong currents, causing sailors to lose their way. Along with the Skeleton Coast further north, it is notorious as the site of many shipwrecks. Some of these wrecked ships can be found as much as 50 metres inland, as the desert is slowly creeping westwards into the sea, reclaiming land over a period of many years.

The Namib is an important location for the mining of tungsten, salt and diamonds.

Access is via light aircraft from Windhoek (the capital of Namibia, about 480 km east of the centre of the desert), Swakopmund and Walvis Bay at the north end of the desert, or overland on gravel roads.