Blue-headed parrots are noisy birds and make light, high-pitched squeaking sweenk calls.

The blue-headed parrot was formally described in 1766 by the Swedish naturalist Carl Linnaeus in the twelfth edition of his Systema Naturae.

In 1760 Brisson had published a description of "Le perroquet a teste bleue de la Guiane" from a preserved specimen that had been collected in French Guiana.

[4] In 1764 Edwards had included a description and a hand-coloured etching of a live bird in the third volume of his Gleanings of Natural History.

In addition to the well-known nominate subspecies found throughout most of the species' South American range, there are two more localized subspecies: rubrigularis from southern Central America and the Chocó has an overall paler plumage and typically a relatively distinct pinkish patch on the throat, and reichenowi from the Atlantic Forest in east Brazil has a paler bill and most of the underparts blue.

In all subspecies the male and the female are alike, and juvenile birds have less blue on the head, as well as red or pinkish feathers around the ceres.

A Pacific Ocean coastal strip continues the range, from southern Ecuador, north to Caribbean areas of northwestern Colombia and western Venezuela.