The African openbill is found in throughout sub-Saharan Africa from Senegal east to Ethiopia and then south as far as KwaZulu-Natal in eastern South Africa. It is a bird of shallow wetlands and can be found wherever its molluscan prey is available, including temporarily flooded pans, flood plains, swamps, marshes, ponds, streams, river shallows, dams, rice paddies, lagoons, lake margins and intertidal mud flats.
The African openbill feeds almostly exclusively on aquatic snails and freshwater mussels. It will, however, also eat terrestrial snail, frogs, crabs, fish, worms, and large insects. It uses its bill to detects its prey, and can use it in such a way that it easily pries open molluscs. It tends to feed singly or in small groups.
The African openbill is mainly resident and non-migratory; however, it may undertake nomadic movements. Sometimes flocks move away from arid regions when the dry season begins.