Kinshasa, formerly named Léopoldville before June 30, 1966, is the capital and largest city of the Democratic Republic of the Congo. Once a site of fishing and trading villages along the Congo River, Kinshasa is now one of the world's fastest-growing megacities. With an estimated population of 16 million residents, it's the most densely populated city in the DRC and the most populous city in Africa. It is Africa's third-largest metropolitan area and the leading economic, political, and cultural center of the DRC. Kinshasa houses several industries, including manufacturing, telecommunications, banking, and entertainment. The city also hosts some of DRC's significant institutional buildings, such as the Palais du Peuple, Palais de la Nation, Court of Cassation, Constitutional Court, Cité de l'Union Africaine, Palais de Marbre, Stade des Martyrs, Immeuble du Gouvernement, Kinshasa Financial Center, and multiple federal departments and agencies.

Brazzaville is the capital and largest city of the Republic of the Congo. Administratively, it is a department and a commune. Constituting the financial and administrative centre of the country, it is located on the north side of the Congo River, opposite Kinshasa, the capital city of the Democratic Republic of the Congo.