The kererū (Hemiphaga novaeseelandiae), also known as kūkupa (northern Māori dialects), New Zealand pigeon or wood pigeon, is a species of pigeon native to New Zealand. Johann Friedrich Gmelin described the bird in 1789 as a large, conspicuous pigeon up to 50 cm (20 in) in length and 550–850 g (19–30 oz) in weight, with a white breast and iridescent green–blue plumage. Two subspecies have been recognised; the second—the Norfolk pigeon of Norfolk Island—became extinct in the early 20th century. Kererū pairs are monogamous, breeding over successive seasons and remaining together when not breeding. They construct nests with twigs in trees, with a single egg clutch.

Found in a variety of habitats across the country, the kererū feeds mainly on fruits, as well as leaves, buds and flowers. Although widespread in both forest and urban habitats, its numbers have declined significantly since European colonisation and the arrival of invasive mammals, such as rats, stoats and possums. However, the results of nationwide bird surveys indicate that there has been a significant recovery in the population in suburban areas. As of 2022, the IUCN Red List classifies the species as least concern, while the Department of Conservation (DOC) classifies the kererū as "not threatened" but conservation dependent.

Considered a taonga (cultural treasure) to the Māori people, the kererū was historically a major food source in Māori culture. However, due to the decline in its population, hunting is illegal. Customary use of kererū is restricted to the use of feathers and bones obtained from dead birds collected by DOC. This issue has received significant public and political attention, as some people argue that bans on kererū hunting are detrimental to Māori traditions. In 2018, the kererū was designated Bird of the Year by the New Zealand organisation Forest & Bird, and in 2019, the exoplanet HD 137388 b was renamed Kererū in its honour.

English ornithologist John Latham wrote about the kererū in his A General Synopsis of Birds in 1783 but did not give it a scientific name. German naturalist Johann Friedrich Gmelin gave it its first formal description in 1789, placing it in genus Columba as C. novaeseelandiae, with Latham naming it Columba zealandica in his 1790 Index Ornithologicus. The genus Hemiphaga was introduced by the French naturalist Charles Lucien Bonaparte in 1854 with the kererū (Hemiphaga novaeseelandiae) as the type species for that genus. The name combines the Ancient Greek hēmi meaning "half", with the end of the genus name Carpophaga, "fruit eating", as Bonaparte saw the genus as related to both that genus and Megaloprepia (now incorporated into Ptilinopus).

Two subspecies are recognised: H. n. novaseelandiae, which is found throughout New Zealand, and the little-studied Norfolk pigeon (H. n. spadicea) of Norfolk Island, now extinct. The subspecies differed in their plumage colour and shape. In 2001, it was proposed that a third subspecies—H. n. chathamensis or the Chatham Islands pigeon—should be raised to full species status as H. chathamensis on the basis of its distinct plumage, larger size and differing bone structure. This has since been widely accepted. Analysis of mitochondrial DNA confirmed the kererū and Norfolk pigeons to be more closely related to each other than to the Chatham pigeon, and that dispersal between the three landmasses most likely occurred during the Pleistocene Epoch.

The kererū belongs to the family Columbidae, and the subfamily Ptilinopinae, which is found throughout Southeast Asia, Malaya, Australia and New Zealand. The members of this subfamily feed largely on fruits, mainly stone fruit. Within the subfamily, the kererū and Chatham Islands pigeon are in a clade with a lineage that has given rise to the topknot pigeon (Lopholaimus antarcticus) of Australia and the mountain pigeons (Gymnophaps) of New Guinea, as shown in the cladogram below.

"New Zealand pigeon" has been designated the official common name of the kererū by the International Ornithologists' Union (IOU). The word kererū (which is both singular and plural) is the most common Māori name, and a variety of mainstream sources now use the name kererū for the species. Spelling Māori loanwords with macrons—that indicate a long vowel—is now common in New Zealand English where technically possible. It is also known as kūkupa and kūkū in some parts of North Island, particularly in Northland, and Latham had reported the name "Hagarrèroo" in 1783. Kererū have also been called "wood pigeons".

The kererū is a large arboreal pigeon weighing 550–850 g (19–30 oz), and is up to 50 cm (20 in) in length, with a wingspan of around 75 cm (30 in). Its appearance is that of a typical pigeon, in that it has a relatively small head, a straight soft-based bill and loosely attached feathers. The sexes have similar plumage. The head, neck and upper breast are dark green with a gold-bronze highlights, while the nape, upper back and secondary coverts are a copper-sheened purple, lightening to a more grey-green on the lower back, rump and the rest of upper surface of the wings. The tail is dark brown with green highlights and a pale edge. The breast is white, and sharply demarcated from the darker parts of its plumage. The undertail and underwing coverts are mainly pale grey. The bill is red with an orange tip, the feet dark red, and eyes are red with a pink orbital ring. Juveniles have a similar colouration but are generally paler with dull colours for the beak, eyes and feet and a shorter tail. The extinct Norfolk Island subspecies had a chestnut mantle, more grey outer wings and rump, a dark purple tail and white under wing and undertail coverts.