The Christmas Island swiftlet was described by the English naturalist Joseph Lister in 1889 with the scientific name Collocalia esculenta natalis.

It is mainly glossy blue-black or green-black above, with dark grey underparts relieved by a prominent white belly and vent.

It builds a small cup-shaped nest for its clutch of two eggs, high up on the cave wall and often sheltered by a stalactite.

The nests are made of dried palm fibres and lichen and are cemented to the cave wall with the bird's saliva.

An application made in 2006 to list the swiftlet as threatened under the Environment Protection and Biodiversity Conservation Act 1999 was unsuccessful.