The yellow-bellied flyrobin (Cryptomicroeca flaviventris) is a species of passerine bird in the Australasian robin family Petroicidae.

The yellow-bellied flyrobin was described in 1860 by the French ornithologists, Jules Verreaux and Oeillet des Murs, from a specimen collected in New Caledonia.

[2] The English ornithologist, Richard Bowdler Sharpe, realised that the specific epithet was preoccupied, and in 1903 he proposed flaviventris as a replacement.

[4] However, a 2009 genetic study showed it to be nested within the flyrobin genus Microeca,[5] and hence it was moved to Microeca, and its common name was changed from yellow-bellied robin to yellow-bellied flyrobin in the online list of world birds maintained by Frank Gill and David Donsker on behalf of the International Ornithological Committee (IOC).

The plumage is similar to members of the genus Eopsaltria: dark olive-grey back, tail and wings, grey head and chest with a slightly lighter throat, and yellow belly and rump.