Mai-Ndombe is one of the 21 newest provinces of the Democratic Republic of the Congo created in the 2015 repartitioning when the former Bandundu province was split-up into the new provinces of Mai-Ndombe, Kwango, and Kwilu. Mai-Ndombe was formed from the Plateaux and Mai-Ndombe districts, with the town of Inongo being elevated to the capital city of the new province.

The 2024 population was estimated to be 2,291,000.

Mai-Ndombe is located in the western Democratic Republic of the Congo. It has an international border with the Republic of the Congo to the west, and borders with several other provinces: Équateur and Tshuapa to the north, Kasaï to the east, and Kwilu and Kinshasa to the south. Most of the province has a tropical savanna climate by the Köppen-Geiger climate classification, except for the northeast, which has areas with a tropical monsoon climate or a tropical rainforest climate.

Currently, there are 8 territories in Mai-Ndombe province, which are:

Mai-Ndombe Province was a separate province from 1962 to 1966, prior the creation of Bandundu Province from the post-colonial political regions of Kwango, Kwilu, and Mai-Ndombe. Presidents (from 1965, governors) were:^{[citation needed]}

A large river boat sank in the province in 2021, killing at least 60 people.