It has been included as a subspecies of the similar buff-necked ibis, but today all major authorities accept the split.

The black-faced ibis was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae.

[2] Gmelin based his description on the "black-faced ibis" that had been described and illustrated in 1785 by the English ornithologist John Lathamin his book A General Synopsis of Birds.

Latham had based his account on a specimen in the Leverian Museum and on drawings in the collection of the naturalist Joseph Banks.

[5] The black-faced ibis is now one of four South American ibises placed in the genus Theristicus that was introduced by the German naturalist Johann Georg Wagler in 1832.