The glaucous macaw is a critically endangered or possibly extinct species of large, blue and grey South American parrot, a member of a large group of neotropical parrots known as macaws. This macaw is closely related to Lear's macaw and the hyacinth macaw. In Guaraní, it is called guaa-obi after its vocalizations.

Macaws are a group of New World parrots that are long-tailed and often colorful, in the tribe Arini. They are popular in aviculture or as companion parrots, although there are conservation concerns about several species in the wild.