Luba-Kasai, also known as CilubĂ or TshilubĂ , Luba-Lulua, is a Bantu language (Zone L) of Central Africa and a national language of the Democratic Republic of the Congo, alongside Lingala, Swahili, and Kikongo ya leta.
An eastern dialect is spoken by the Luba people of the East Kasai Region and a western dialect by the Lulua people of the West Kasai Region. The total number of speakers was estimated at 6.3 million in 1991.