The DRC has a population (2004 estimate) of 53,634,719, with a density of 23 persons per sq km (59 per sq mi). Largely rural, the population is concentrated in the eastern highlands and along rivers.Only about 30% of the population lives in cities. In 1998 the DRC also had a refugee population of about 240,300, many of whom were exiles from instability in Rwanda. The remainder were Burundians, Angolans, and Sudanese, all fleeing upheavals in their countries. Meanwhile, about 252,400 DRC citizens had taken refuge in neighboring countries.

Bantu speakers form a majority of the nation's population and occupy about two-thirds of its area. They include the Luba, Mongo, Kongo, Lunda, and Kasai peoples. Among non-Bantu speakers are Sudanese groups of the north and the Nilotic peoples of the northeast. The Pygmies, the earliest settlers, who came perhaps in late Paleolithic times,inhabit forest and river sites about the nation. More than 200 languages and dialects are spoken in Zaire. Swahili, Tshiluba,Lingala, and Kikongo are the four national languages. They are used in local trading and radio broadcasting. French is the official language and the language of instruction, business, administration, and international communications. Lingala is the official language of the military and is widely spoken in Kinshasa. In religious affiliation, Roman Catholics predominate, followed by Protestants and members of a local Christian sect, the Church of Simon Kimbangu.