a Bantu language (Bantu languages) of the Benue-Congo branch (Benue-Congo languages) of the Niger-Congo language family. Kongo is related to Swahili (Swahili language), Shona, and Bembe, among others. Kikongo is the name used by its speakers. There are many dialects of Kongo; San Salvador Kongo, spoken in Congo (Kinshasa) (Congo) and Angola, has more than 1.5 million speakers and is often listed as a separate language because it is not mutually intelligible with other Kongo dialects. There are more than seven million native speakers of Kongo, many of whom live in western Congo (Kinshasa), where Kongo is a national language. The remaining native speakers live in Congo (Brazzaville) (Congo) and northern Angola. An additional seven million Africans claim Kongo as a second language.

Kongo was one of the first African languages to be studied and documented by Western scholars. The first such documentation came in 1591 when the Italian Filippo Pigafetta included several words in Kongo in a description of the Kongo area that he based on the work of an earlier Portuguese traveler. In 1650 a multilingual dictionary of Kongo that reportedly included explanations in Portuguese, Latin, and Italian was produced by Giacinto Brusciotto, also an Italian; however, material proof of the dictionary does not exist. In 1652 a 7,000-word dictionary of Kongo was produced, and in 1659 Brusciotto wrote the first grammatical analysis of Kongo. Brusciotto's work is still praised for its accurate understanding of the nominal and verbal systems of Kongo, despite the lack of analogous systems in Latin or any other previously studied grammars.