The collared aracari was described by the Spanish naturalist Francisco Hernández (1514–1587) in his work Rerum medicarum Novae Hispaniae thesaurus, seu, Plantarum animalium mineralium Mexicanorum historia which was published posthumously in 1651.

[5] When the German naturalist Johann Friedrich Gmelin revised and expanded Carl Linnaeus's Systema Naturae in 1788 he included the collared aracari and cited the descriptions by earlier ornithologists.

[7] When John Gould published a hand-coloured illustration of the collared aracari in 1854 he commented: "We find in the writings of the older authors — Gmelin, Latham, and others — a species of this family called Ramphastos torquatus, which may have been intended to indicate the present bird, but their descriptions and measurements are somewhat inapplicable; at the same time it is the only species yet discovered having a distinct reddish collar at the back of the neck, and there is no other bird which agrees so well with their obscure descriptions".

[9] The collared aracari is now one of 14 species placed in the genus Pteroglossus that was introduced in 1811 by Johann Karl Wilhelm Illiger.

[10][11] The International Ornithological Committee (IOC) and BirdLife International's Handbook of the Birds of the World (HBW) recognize three subspecies:[11][12] The South American Classification Committee of the American Ornithological Society and the Clements taxonomy include two other subspecies that IOC and HBW separate as the stripe-billed aracari (P. sanguineus) and pale-mandibled aracari (P.

Adults of the nominate subspecies have mostly glossy black upperparts with a narrow cinnamon rufous collar at the base of the nape and bright red lower back, rump, and uppertail coverts.

Juvenile collared aracaris are much duller than adults, with a sooty-black head and chest and brownish olive upperparts.

The red rump and yellow underparts are paler, and the breast spot, belly band, and bill pattern are indistinct.

P. t. nuchalis is also similar to the nominate, but its breast spot is usually larger and the white basal line on the bill is wider.

[13] The most common call is described as "a high, sharp, squeaky, note, such as seek, pseek, pink or penk, or a two-parted pi-cheet or squi-zeek."

[13] The collared aracari's diet is mostly fruit but it also feeds on large insects, the eggs and nestlings of other birds, and other small vertebrates.