The Nicobar pigeon (Caloenas nicobarica, Car: ma-kūö-kö) is a bird found on small islands and in coastal regions from the Andaman and Nicobar Islands, India, east through the Malay Archipelago, to the Solomons and Palau. It is the only living member of the genus Caloenas alongside the extinct spotted green pigeon, and is the closest living relative of the extinct dodo and Rodrigues solitaire.
It is a large pigeon, measuring 40 cm in length. The head is grey, like the upper neck plumage, which turns into green and copper hackles. The tail is very short and pure white. The rest of its plumage is metallic green. The cere of the dark bill forms a small blackish knob; the strong legs and feet are dull red. The irises are dark.
Females are slightly smaller than males; they have a smaller bill knob, shorter hackles and browner underparts. Immature birds have a black tail and lack almost all iridescence. There is hardly any variation across the birds' wide range. Even the Palau subspecies C. n. pelewensis has merely shorter neck hackles, but is otherwise almost identical.
It is a very vocal species, giving a low-pitched repetitive call.