right|thumb|Blue-and-yellow Macaw eating a walnut held by a foot Parrots, also known as psittacines ( ), are birds of around 8,600 species in 86 genera that make up the order Psittaciformes, found in most warm and tropical regions. The order is subdivded in three families: the Psittacidae (true parrots), the Cacatuidae (cockatoos) and the Nestoridae. Parrots have a pan-tropical distribution with several species inhabiting the temperate Southern Hemisphere as well. The greatest diversity of parrots is found in South America and Australasia.

Characteristic features of parrots include a strong curved bill, an upright stance, strong legs, and clawed zygodactyl feet. Most parrots are predominantly green, with other bright colors, and some species are multi-colored. Cockatoo species range from mostly white to mostly black, and have a mobile crest of feathers on the top of their heads. Most parrots are monomorphic or minimally sexually dimorphic. Extant species range in size from the Buff-faced Pygmy-parrot, at under 10 g (0.35 oz.) in weight and 8 cm (3.2 inches) in length, to the Hyacinth Macaw, at 1.0 meter (3.3 feet) in length, and the Kakapo, at 4.0 kg (8.8 lbs) in weight. They are the most variably sized bird order in terms of length.

The most important components of most parrots' diets are seeds, nuts, fruit, buds and other plant material, and a few species also eat insects and small animals, and the lories and lorikeets are specialised to feed on nectar from flowers, and soft fruits. Almost all parrots nest in tree holes (or nestboxes in captivity), and lay white eggs from which emerge altricial (helpless) young.

Parrots, along with crows, jays and magpies, are some of the most intelligent birds, and the ability of some parrot species to imitate human voices enhances their popularity as pets. Trapping of wild parrots for the pet trade, as well as other hunting, habitat loss and competition from invasive species, have diminished wild populations, and parrots have been subjected to more exploitation than any other group of birds. Recent conservation measures to conserve the habitats of some of the high-profile charismatic parrot species has also protected many of the less charismatic species living in the ecosystem.Snyder, N; McGowan, P; Gilardi, J; & A Grajal (2000), Parrots: Status Survey and Conservation Action Plan, 2000-2004. Chapter 1. vii. IUCN ISBN 2-8317-0504-5. Chapter 2. page 12.

Origins and evolution

A single 15 mm fragment from a lower bill (UCMP 143274), found in Lance Creek Formation deposits of Niobrara County, Wyoming, has been suggested as the first parrot fossil. Of Late Cretaceous age, it is about 70 million years old. But subsequent reviews have established that this fossil is almost certainly not from a bird, but from a caenagnathid theropod—a non-avian dinosaur with a birdlike beak.