The Thunderbird is a legendary creature in certain North American indigenous peoples' history and culture. It is considered a "supernatural" bird of power and strength. It is especially important, and richly depicted, in the art, songs and oral histories of many Pacific Northwest Coast cultures, and is found in various forms among the peoples of the American Southwest and Great Plains. Thunderbirds were major components of the Southeastern Ceremonial Complex of American prehistory.

The Thunderbird's name comes from the common belief that the beating of its enormous wings causes thunder and stirs the wind. The Lakota name for the Thunderbird is Wakį́yą, from wakhą, meaning "sacred", and kįyą, meaning "winged". The Kwakwaka'wakw have many names for the Thunderbird and the Nuu-chah-nulth (Nootka) called him Kw-Uhnx-Wa. The Ojibwa word for a thunderbird that is closely associated with thunder is animikii, while large thunderous birds are known as binesi.

Across many North America indigenous cultures, the Thunderbird carries many of the same characteristics. It is described as a large bird, capable of creating storms and thundering while it flies. Clouds are pulled together by its wingbeats, the sound of thunder made by its wings clapping, sheet lightning the light flashing from its eyes when it blinks, and individual lightning bolts made by the glowing snakes that it carries around with it. In masks, it is depicted as many-colored, with two curling horns, and, often, teeth within its beak. The believed that the giant Thunderbird could shoot lightning from its eyes. Origins of the belief may lie in the tendency of large birds to take advantage of the warm updrafts which precede large storms, giving the impression that violent weather followed in their wake.