Mauritania is located on the West African coast bordered by the Atlantic Ocean on the west, Senegal on the southwest, Mali on the east and southeast, Algeria on the northeast, and Western Sahara on the northwest. It is named after the ancient Berber kingdom of Mauritania. The capital and largest city is Nouakchott, located on the Atlantic coast.

Approximately three quarters of Mauritania is desert or semi-desert. As a result of extended, severe drought, the desert has been expanding since the mid-1960s. To the west, between the ocean and the plateaus, are alternating areas of clayey plains (regs) and sand dunes (ergs), some of which shift from place to place, gradually moved by high winds. The dunes generally increase in size and mobility toward the north. The country is generally flat, forming vast, arid plains broken by occasional ridges, cliff like outcroppings, sandstone mesas and plateaus. Spring-fed oases lie at the foot of some of the ridges. Isolated peaks, often rich in minerals, rise above the plateaus.

A majority of the population still depends on agriculture and livestock for a livelihood, even though most of the nomads and many subsistence farmers were forced into the cities by recurrent droughts in the 1970s and 1980s. The nation's coastal waters are among the richest fishing areas in the world, but overexploitation by foreigners threatens this key source of revenue. The country's first deepwater port opened near Nouakchott in 1986.