The buff-necked ibis, also known as the white-throated ibis, is a fairly large ibis found widely in open habitats of eastern and northern South America. It formerly included the similar black-faced ibis as a subspecies, but that species is almost entirely restricted to colder parts of South America, has a buff lower chest, and lacks the contrasting large white wing-patches.

The ibis are a group of long-legged wading birds in the family Threskiornithidae that inhabit wetlands, forests and plains. "Ibis" derives from the Latin and Ancient Greek word for this group of birds. It also occurs in the scientific name of the western cattle egret mistakenly identified in 1757 as being the sacred ibis.