The Puerto Rican amazon (Amazona vittata), also known as the Puerto Rican parrot (Spanish: cotorra puertorriqueña) or iguaca (Taíno), is the only extant parrot endemic to the archipelago and island of Puerto Rico. Measuring 28–30 cm (11.0–11.8 in), the bird is a predominantly green parrot with a red forehead and white rings around the eyes. Belonging to the Neotropical genus Amazona, its closest relatives are believed to be the Cuban amazon (Amazona leucocephala) and the Hispaniolan amazon (Amazona ventralis).

The Puerto Rican amazon reaches sexual maturity at between three and four years of age. It reproduces once a year and is a cavity nester. Once the female lays eggs she will remain in the nest and continuously incubate them until hatching. The chicks are fed by both parents and will fledge 60 to 65 days after hatching. This parrot's diet is varied and consists of flowers, fruits, leaves, bark and nectar obtained from the forest canopy.

The species is the only remaining native parrot to Puerto Rico and has been listed as critically endangered by the World Conservation Union since 1994. Once widespread and abundant, the population declined drastically in the 19th and early 20th centuries with the removal of most of its native habitat; the species has completely vanished from Vieques and Mona Island. Conservation efforts commenced in 1968 to save the bird from extinction.

The Puerto Rican amazon was described by the French polymath Georges-Louis Leclerc, Comte de Buffon in 1780 in his Histoire Naturelle des Oiseaux. The bird was also illustrated in a hand-coloured plate engraved by François-Nicolas Martinet in the Planches Enluminées D'Histoire Naturelle which was produced under the supervision of Edme-Louis Daubenton to accompany Buffon's text. Neither the plate caption nor Buffon's description included a scientific name but in 1783 the Dutch naturalist Pieter Boddaert coined the binomial name Psittacus vittatus in his catalogue of the Planches Enluminées. Buffon mistakenly believed that his specimen had been collected in the French colony of Saint-Domingue (modern Haiti), rather than in Puerto Rico. The Puerto Rican amazon is now placed in the large Neotropical genus Amazona that was introduced by the French naturalist René Lesson in 1830. The specific epithet vittatus is Latin for "banded".

Birds in the genus Amazona are commonly known as amazons. They have also been given the generic epithet of "parrot" by the American Ornithologists' Union, and hence "Puerto Rican parrot" is an alternative common name in North America. The indigenous Taíno people called it the iguaca, an onomatopoeic name that resembled the parrots' flight call.

There are two recognized subspecies:

The various native parrot species in the West Indies are assumed to be descended from a singular group that immigrated to the Caribbean at some point. Some small species would have encountered problems traversing large bodies of water, but parrots have flight strength and various behavioral characteristics that would facilitate "over-water" dispersion. Most Caribbean bird species originate from Central, North and South America. The Amazona species found in the Caribbean are divided in two groups: five mid-sized species found in the Greater Antilles and seven large species in the Lesser Antilles. All the Greater Antillean amazons display characteristics leading to suppositions of relatedness, including predominantly green-toned color patterns and white rings around the eyes. Russello and Amato conclude that all Greater Antillean Amazona descend from Amazona albifrons with Amazona vittata, Amazona leucocephala, and Amazona ventralis constituting a complex, a cluster of species so closely related that they intergrade.

British ornithologist David Lack considered that the Puerto Rican amazon had evolved from the Hispaniolan amazon (A. ventralis) found in Hispaniola, but it has since been argued that he omitted some elements in his analysis, including the similarities found between the black-billed amazon (A. agilis) of Jamaica and the Puerto Rican amazon. Subsequent studies showed that size and color patterns were not sufficient to assess evolutionary relationships, and that patterns changed with relative ease even within members of the same species. The research concluded that the Puerto Rican amazon may share a common ancestor with the Jamaican A. agilis. However, recent phylogenetic studies show that the Puerto Rican amazon is more closely related to the Hispaniolan amazon and the Cuban amazon than to the black-billed amazon.