In the mythology of the Algonquian-speaking tribes of Native Americans, the Wendigo is a malevolent supernatural creature. It is usually described as a giant with a heart of ice; sometimes it is thought to be entirely made of ice. Its body is skeletal and deformed, with missing lips and toes.

The first accounts of the Wendigo myth by explorers and missionaries date back to the 17th century. They describe it rather generically as a werewolf, devil or cannibal.

The Wendigo was usually presumed to have once been human. Different origins of the Wendigo are described in variations of the myth. A hunter may become the Wendigo when encountering it in the forest at night, or when becoming possessed by its spirit in a dream. When the cannibalistic element of the myth is stressed, it is assumed that anyone who eats corpses in a famine becomes a Wendigo as a result. The only way to destroy a Wendigo is to melt its heart of ice. In recent times, it has been identified with sasquatch or bigfoot by cryptozoologists, but there is little evidence in the indigenous folklore for it being a similar creature.

Perhaps this myth was used as a deterrent and cautionary tale among northern tribes whose winters were long and bitter and whose hunting parties often were trapped in storms with no recourse but to consume members of their own party. It could be indicative of starvation that the Wendigo is said to consume moss and other unpalatable food when human flesh is unavailable. Its physical deformities are suggestive of starvation and frostbite, so the Wendigo may be a myth based on a personification of the hardships of winter and the taboo of cannibalism.