These are the rivers with the largest drainage areas in the world. A drainage area is any area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water. The South American Amazon–Ucayali–Tambo–Ene–Apurímac receives inflows from the largest drainage area, a size of 7 million km², and flows out primarily to the Atlantic Ocean.

The African rivers, Congo–Chambeshi (Zaïre) river and Nile–Kagera river, have drainage areas of 3.6 million km² (second largest) and 3.2 million km² (third largest) respectively The Congo–Chambeshi (Zaïre) river outflows to the Atlantic Ocean as well, while Nile–Kagera river outflows to the Mediterranean sea.