The Pacific koel was formally described by the Swedish naturalist Carl Linnaeus in 1766 in the twelfth edition of his Systema Naturae.

[2] Linnaeus based his account on the "Le Coucou noir des Indes" that had been described and illustrated in 1760 by the French zoologist Mathurin Jacques Brisson in his multi-volume work Ornithologie.

[4][6][7] Eight subspecies are recognised:[5] The Pacific Koel can be identified by its black plumage, often tinted with blue and green, and red eyes.

The species is sexually dimorphic: the female has brown plumage along the back with white spots and the underbelly is often cream coloured with fine black stripes.

It is found in forest, woodland, plantations and gardens from Wallacea east to the Solomon Islands and south to northern and eastern Australia.