The Pacific imperial pigeon was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae.

[4][5] The genus name Ducula is from the Latin dux genitive ducis meaning "leader".

[6] Two subspecies are recognised:[5] The Pacific imperial pigeon is 36–41 cm (14–16 in) in overall length and weighs 370–420 g (13–15 oz).

Individuals may gather to form large flocks in fruiting trees and travel some distances to forage.

[7] In a study conducted in Tonga, Pacific imperial pigeons consumed the fruit of 38 species of plant across 24 families.

[7] The species has suffered from habitat loss and hunting pressure, and has declined locally in some areas, but it remains common over much of its range, and is listed as least concern by the IUCN.