The population of Belgium is 10,258,000. Nearly 61 % live in the Flanders region. The overall population density, one of the highest in Europe, is 336 persons per sq km. The largest concentrations were in the Brussels, Antwerp, Liège, and Ghentindustrial areas, as well as in the narrow industrial region between Mons and Charleroi. In recent decades the Limbourg city region has increased in population because of industrial development in that area. Almost 10.5 % of all Belgians live in Brussels, which is also home to large numbers of foreign guest workers. Some 97 % of the population is classified as urban.

The population of Belgium is separated into three linguistic communities. In the north the Flemings, who constitute more than half of Belgium's population, speak Netherlandic. Although speakers of English usually call the Netherlandic spoken in The Netherlands “Dutch” and that spoken in Belgium “Flemish,” both are actually the same language . In the south the French-speaking Walloons make up about one-third of the nation's population. About one-tenth of the population is completely bilingual, but a majority have some knowledge of both French and Flemish. The German-language region in eastern Liège province, containing fewer than 1 % of the Belgians, consists of 9 communes around Eupen and Saint-Vith.