Nyssa aquatica, commonly called the water tupelo, cottongum, wild olive, large tupelo, tupelo-gum, or water-gum, is a large, long-lived tree in the tupelo family, Nyssaceae, that grows in swamps and floodplains in the Southeastern United States.

Nyssa aquatica trunks have a swollen base that tapers up to a long, clear bole, and its root system is periodically underwater. Water tupelo trees often occur in pure stands.