The purple-throated cotinga (Porphyrolaema porphyrolaema) is a species of bird in the cotinga family, Cotingidae. It is found in the western Amazon rainforest of South America; its range extends from southern Colombia south through eastern Ecuador and Peru and east through extreme northwestern Bolivia and into western Amazonian Brazil. It lives in the canopy or along the borders of humid forest throughout its range. The purple-throated cotinga is monotypic within the genus Porphyrolaema and has no known subspecies. It is one of the smaller cotinga species and expresses strong sexual dimorphism. Males have black upperparts with a bold white wingstripe and white edges to the tertial feathers and a white belly with some black barring on the rear flanks. The throat is a deep purple, giving the bird both its common and scientific names. Females are dark brown with pale buffy margins on the upperparts, buffy cinnamon with black barring on the underparts, and rufous on the throat. The male has a powerful voice.

Little research has been done on this species, and not much is known about its ecology. The purple-throated cotinga is primarily frugivorous, although it does occasionally eat small insects. A solitary male attracts a female by perching in the canopy and letting the sunlight reflect off its iridescent feathers. It is suspected to breed year-round and is non-migratory. Despite being considered naturally uncommon or rare across its vast range, the purple-throated cotinga is listed as a species of Least Concern.

The purple-throated cotinga is strongly sexually dimorphic as male and female purple-throated cotingas have few similarities in their plumage. The male has black upperparts, including the head, wings, and tail. The feathers on the bird's back to its uppertail coverts, as well as its upperwing coverts, have white fringes, giving it a scaled appearance. There is also a conspicuous white wingstripe and white edges to the tertial feathers. Additionally, the male has a deeply purple throat and a white belly, with some black barring on its rear flanks.

In contrast, the female purple-throated cotinga is a dark brown with pale buffy margins on the upperparts. The underparts are a buffy cinnamon with black barring. The throat is a deeper, unbarred rufous in coloration. The female's tail feathers are longer and more pointed at the tip than those of the male. The juvenile purple-throated cotinga resembles a paler, buffier female; the plumage of the immature is undescribed.

The adult purple-throated cotinga is about 16.5 to 18.5 cm (6.5 to 7.3 in) in length and weighs an average of 49 to 60 g (1.7 to 2.1 oz), with males being very slightly smaller than females. The cotinga has a very wide bill with a strongly arched culmen and weakly developed rictal bristles. The bird's iris is dark brown, while the bill and legs are black. The tail is square-ended.

This species has a powerful if infrequently-used voice, unlike the structurally-similar Cotinga species, which are mostly silent. The male's call is a high, plaintive "preeeeeer" that lasts for one or two seconds while dropping in pitch and is regularly repeated from a treetop perch. It is also known to produce a tremulous "werleeyooo" that can be interspersed with the "preeeeeer" call.