Kasaï was a province of the Belgian Congo and the successor Republic of the Congo (Léopoldville).

Kasaï was named after the Kasai River, a major left tributary of the Congo River that provides access to the region. By 1910 a factory of the Kasai Company had been established near Misumba, which had about two thousand inhabitants.^[1] The company had made successful trial rubber plantations.^[2] The company also bought rubber and ivory from the local people, some of whom used it to buy liquor from the Portuguese territory (Angola).^[3]

In 1914 the Belgian Congo was organized into four large provinces: Congo-Kasai, Équateur, Orientale Province and Katanga.^[4] in 1933 they were reorganized into six provinces, named after their capitals, and the central government assumed more control. Congo-Kasai was divided into the new provinces of Léopoldville and Lusambo, named after the city of Lusambo. In 1947 Lusambo Province was renamed to Kasaï.^[5]

Kasaï became an autonomous province of the Congo republic on 30 June 1960.^[6] On 14 August 1962 Kasaï was divided into five new provinces: Lomami, Luluabourg, Sankuru, Sud-Kasaï and Unité Kasaïenne. On 25 April 1966 Luluabourg and Unité Kasaïenne were united to form Kasaï-Occidental, while Lomami, Sankuru, and Sud-Kasaï were united in the new province of Kasaï-Oriental.^[6]

• List of governors of Kasaï (former province)
• History of the Kasai region