The Namib Desert is recognised as one of the oldest deserts in the world. In this Chapter, its age and evolution through the past 55 million years are described, and the source and mechanisms of transportation and deposition of the dunes that cover large areas of the Namib coast are summarised. The role of the South Atlantic Anticyclone, the Benguela Current, and wind and fog as key factors in the evolution and maintenance of the desert ecosystems are described. The Namib Desert ecoregion occurs along the Angolan coast as a narrow belt from the Cunene River to the Carunjamba River. The diverse landscapes and their sparse vegetation mantle are photographically illustrated. Both flora and fauna have many disjunct distributions linking them with the Horn of Africa suggesting the existence of an arid corridor across eastern Africa during the Pleistocene. The flora and fauna of the Namib Desert, and in particular, the biology of the enigmatic gymnosperm, Welwitschia mirabilis, are discussed.