Choanozoa is a clade of opisthokont eukaryotes consisting of the choanoflagellates (Choanoflagellatea) and the animals (Animalia, Metazoa).

This proposed homology was however thrown into some doubt in 2013 by the still controversial suggestion that ctenophores, and not sponges, are the sister group to all other animals.

[5][6] More recent genomic work has suggested that choanoflagellates possess some of the important genetic machinery necessary for the multicellularity found in animals.

The name "Choanozoa" was first used by protozoologist Thomas Cavalier-Smith in 1991 to refer to a group of basal protists that later proved not to form a clade.

[4] Although the last common ancestor of the Choanozoa cannot be reconstructed with certainty, Budd and Jensen suggest that these organisms formed benthic colonies that competed for space amongst other mat-forming organisms known to have existed during the Ediacaran Period some 635–540 million years ago.