As of July 2016, the International Union for Conservation of Nature (IUCN) lists 394 critically endangered arthropod species, including 86 which are tagged as possibly extinct. 4.1% of all evaluated arthropod species are listed as critically endangered. The IUCN also lists three arthropod subspecies as critically endangered. No subpopulations of arthropods have been evaluated by the IUCN. This is a complete list of critically endangered arthropod species and subspecies as evaluated by the IUCN. Species considered possibly extinct by the IUCN are marked as such.