Mbandaka lies on the east bank of the Congo River below the mouth of the Tshuapa River, a tributary of the Congo. South of the Ngiri Reserve, a large area of swamp forest on the opposite bank of the Congo, it lies at the center of the Tumba-Ngiri-Maindombe Ramsar wetland.

Mbandaka was founded in 1883 by Henry Morton Stanley with the name of "Équateurville". The town hall is about 4 kilometres (2.5 mi) north of the equator. Mbandaka is one of the closest to the equator of any substantial city in the world. Stanley placed a large "Equator Stone" near the riverbank south of the city to mark the point where he believed the equator crossed the river. It remains there today. Due to its symbolic location close to the equator and the Congo River, there were early plans to locate the capital of the Congo Free State in Mbandaka, but they never came off the drawing board. These plans included infrastructure for an estimated population of 100,000 people, a train station, a Catholic cathedral, a governor's residence, and a palace for future visits of Leopold II of Belgium.

When someday comes you'll need to get in.

When someday comes you'll need to be able to get around.