As of December 2019, the International Union for Conservation of Nature (IUCN) listed 223 critically endangered avian species, including 19 which are tagged as possibly extinct or possibly extinct in the wild. 2% of all evaluated avian species are listed as critically endangered. No subpopulations of birds have been evaluated by the IUCN.
Additionally 55 avian species (0.48% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status. As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN. While the category of data deficient indicates that no assessment of extinction risk has been made for the taxa, the IUCN notes that it may be appropriate to give them "the same degree of attention as threatened taxa, at least until their status can be assessed".
This is a complete list of critically endangered avian species evaluated by the IUCN. Species considered possibly extinct by the IUCN are marked as such. Where possible common names for taxa are given while links point to the scientific name used by the IUCN.
There are 23 parrot species assessed as critically endangered.