Macaws are small to large, often colourful New World parrots. Of the many different Psittacidae (true parrots) genera, six are classified as macaws: Ara, Anodorhynchus, Cyanopsitta, Primolius, Orthopsittaca, and Diopsittaca. Previously, the members of the genus Primolius were placed in Propyrrhura, but the former is correct as per ICZN rules. Macaws are native to Mexico, Central America, South America, and formerly the Caribbean. Most species are associated with forest, especially rainforest, but others prefer woodland or savanna-like habitats.

Large, dark (usually black) beaks and relatively hairless, light colored, medial facial (facial patch) areas distinguish macaws. Sometimes the facial patch is smaller in some species, and limited to a yellow patch around the eyes and a second patch near the base of the beak in the members of the genus Anodorhynchus, or Hyacinth Macaw. It has been documented that a Macaw's facial feathers are unique as a human fingerprint.

Some of the macaw species are popularly known for their impressive size. The largest parrot in length and wingspan is the Hyacinth Macaw. The heaviest macaw is the Buffon's, although the heaviest parrot is the flightless Kakapo. While still relatively large parrots, the macaws of the genera Cyanopsitta, Orthopsittaca and Primolius are significantly smaller than the members of Anodorhynchus and Ara. The smallest member of the family, the Red-shouldered Macaw, is no larger than some parakeets of the genus Aratinga.

Macaws, like other parrots, as well as toucans and woodpeckers, are zygodactyl, having their first and fourth toe pointing backwards.