The white-faced ibis (Plegadis chihi) is a wading bird in the ibis family, Threskiornithidae.

This species breeds colonially in marshes, usually nesting in bushes or low trees. Its breeding range extends from the western United States south through Mexico, as well as from southeastern Brazil and southeastern Bolivia south to central Argentina, and along the coast of central Chile. Its winter range extends from southern California and Louisiana south to include the rest of its breeding range.

In its non-breeding plumage, the white-faced ibis is very similar to the glossy ibis except that it tends to be slightly smaller and its plumage has a somewhat warmer color. Breeding adults have a pink, bare face bordered with white feathers (rather than a bluish bare face with no bordering feathers), a grey bill, and brighter-colored, redder legs. Adults have red eyes year-round, whereas glossy ibises have dark eyes. Juveniles of the two species are nearly identical.

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The white-faced ibis occurs in Canada, the United States, and Central America, and a second subspecies inhabits the southern half of South America, east of the Andes Mountains. In 2012, the total population size was estimated to be 1.2 million individuals, and increasing. The IUCN rates it as being of Least Concern.

Migration and interchange between North and South American subspecies does not occur. Within North America, birds breeding in northern areas of the range move south to wintering areas. For example, breeders in northern California and southern Oregon move to wintering areas in southern California and México or Central America. Some birds breeding in Yellowstone in Wyoming will overwinter in areas such as Texas and coastal Gulf of Mexico regions.

The white-faced ibis bears a strong resemblance to the related glossy ibis, and in the past was sometimes considered to be a subspecies of the glossy ibis. Another theory was that a small population of glossy ibis dispersed to the Americas, which became isolated and evolved into a separate species. However, recent molecular phylogenetic studies show that the white-faced ibis may actually be paraphyletic. In fact, members of the white-faced ibis populations in the United States appear to be more closely related to glossy ibises than to members of white-faced ibis populations in Southern Brazil.

The white-faced ibis eats a variety of organisms, including many invertebrates such as insects, leeches, snails, crayfish and earthworms. It may also eat vertebrates such as fish, newts, and frogs. Its feeding style is to use its bill to probe for prey.