The population of the Congo comprises four major ethnic groups separated into about 75 smaller groups. The Kongo, the major ethnic group, accounting for about one-half of the total population, occupy the section southwest of Brazzaville. The M’Bochi live in the area where the savanna and forest meet in the northern region; the Sangha also inhabit the northern forest zone; and the Teke live in the central region. About 12,000 pygmies also live in the nation.

Congo's sparse population is concentrated in the southwestern portion of the nation, leaving the large areas of tropical jungle in the north virtually uncolonised. Thus, Congo is one of the most urbanized countries in Africa, with 85% of its total population living in a few urban areas; namely, in Brazzaville, Pointe-Noire, or one of the small cities or villages lining the 332-mile railway which connects the two cities. In southern rural areas, industrial and commercial activity suffered as a consequence of the civil wars. Except in Kouilou province and Pointe Noire, commercial activity other than subsistence activity came nearly to a halt. A slow recovery began in 2000. Before the 1997 war, about 9,000 Europeans and other non-Africans lived in Congo, most of whom were French. Only a fraction of this number remains.