The black-headed ibis (Threskiornis melanocephalus), also known as the Oriental white ibis, Indian white ibis, and black-necked ibis, is a species of wading bird of the ibis family Threskiornithidae which breeds in the South and Southeast Asia from India to the west and as far east as Japan. It is the only native ibis species in its range that has an overall white plumage with a black neck and head. The down-curved beak and legs are also black. Though often referred to as a wetland species, the black-headed ibis forages in a range of natural and man-made habitats. This species of ibis nests only during the rainy season.

The black-headed ibis is one of several large waterbird species in south and south-east Asia, with adults measuring 65–76 cm in length. The white plumage is starkly contrasted against a conspicuous naked black neck and head, and black down-curved beak. Tails of adults bear light grey ornamental feathers that turn jet black during the breeding season. During the breeding season, bare patches under the wing turn blood-red. The head of some breeding adults gain a blueish tinge, or very rarely have a pink or bright red patch behind the neck. Some breeding adults also develop tufts of white feathers behind the neck, and rarely also get a yellowish colouration on the breast and back. Sexes are identical but juveniles are identifiable from adults in having greyish feathering on the neck and speckled brown-grey feathering on the wings and back. Like storks and spoonbills, it lacks a true voice-producing mechanism and is silent except for ventriloquistic grunts uttered by pairs at the nest.