This small duck has a solidly chocolate-brown ‘skull cap’, white cheeks, and a distinctive pink-red bill with a dark saddle. In flight, the buff flight feathers with a black stripe are distinctive on otherwise all-brown wings. It prefers foraging on open fresh water, with seeds and plant matter forming the majority of its diet. The similar Blue-billed Teal differs from Red-billed Duck by being smaller and having a silvery-blue bill and dark smudges on the cheeks. Cape Teal and Bernier’s Teal (the latter endemic to Madagascar) both lack the strongly contrasting face pattern of Red-billed Duck.