The Luapula River is a north-flowing river of central Africa, within the Congo River watershed. It rises in the wetlands of Lake Bangweulu (Zambia), which are fed by the Chambeshi River. The Luapula flows west then north, marking the border between Zambia and the Democratic Republic of the Congo before emptying into Lake Mweru. The river gives its name to Zambia's Luapula Province.

The Luapula drains Lake Bangweulu and its swamps into which flows the Chambeshi River, the source of the Congo. There is no single clear channel connecting the two rivers and the lake, but a mass of shifting channels, lagoons and swamps, as the explorer David Livingstone found to his cost. (He died exploring the area, and one of his last acts was to question Chief Chitambo about the course of the Luapula.) The channel boldly marked as the 'Luapula' and confidently shown on many maps flowing south out of Lake Bangweulu at 11°25'S 29°49'E can be seen on satellite images such as Google Earth to actually peter out into green vegetation around 11°46'S 29°48'E.

Below the Bangweulu swamps and floodplain, the Luapula flows steadily in an arc south-west turning north-west then north, with some rapids and well-known set of cataracts, Mambilima Falls near the main road. A far less well-known site is Tangwa, about 40 kilometres (25 mi) south where the river has eroded a gap through rocky hills carving huge caves, arches, and potholes, and leaving giant boulders, including two balancing rocks called 'God's Corn Bin'.

From the Chembe Bridge to Lake Mweru, the 300 kilometres (190 mi) long Luapula Valley has a higher rural population than the plateau through which it cuts to a depth of up to 500 metres (1,600 ft). The river is known for this valley and for its long thin delta entering Lake Mweru, usually referred to as the Luapula Swamps. The well-populated part of the valley starts north from Mambilima Falls, and along the rest of its length is nicknamed 'Mwapoleni Road', after the Chibemba greeting called out as people pass each other.

For many practical study purposes, the lower Luapula and Mweru can be considered as one entity. They lie in a rift valley or graben once considered separate from the East African Rift but now seen as a branch of it. Mweru, however, drains not into Lake Tanganyika in the Albertine Rift but via the Luvua River, which has cut a deep, narrow zigzag valley to join the Lualaba River, as the upper Congo is named. The Luapula is part of the longest tributary of the Congo, and hence, by convention, is part of its source, even though the upper Lualaba carries more water.

Overlying the edge of the rift valley 60 kilometres (37 mi) west of the Luapula Swamps is the Luizi structure, a 12.6 kilometres (7.8 mi) wide series of concentric rings. It has been recently confirmed as a meteoritic impact crater (an astrobleme) formed less than 600 million years ago.

The swamps stretch along the last 100 kilometres (62 mi) of the river before it reaches the lake, and for much of that, they are 30 kilometres (19 mi) wide, covering an area of about 2,500 square kilometres (970 sq mi). There are four inhabited islands in the DR Congo part of the delta, including the largest in the system, which is accessible overland during the dry season. Zambia has three inhabited islands in the delta including Chisenga Island. There are also many lagoons, the largest of which is Mofwe Lagoon on the Zambian side.

As in the Bangweulu Swamps, floating beds of papyrus are a feature of the swamps, which often block channels and change the shape of lagoons. However, the main river channel does not get blocked and stays consistently about 400 metres (1,300 ft) wide. It has not developed the branching channels typical of river deltas.