The azure-crested flycatcher was first described in 1875 by ornithologist Edgar Leopold Layard, Administrator of the Government of the Colony of Fiji at the time.

[6] They are not closely related to their namesakes either, the Old World flycatchers of the family Muscicapidae; early molecular research in the late 1980s and early 1990s revealed the monarchs belong to a large group of mainly Australasian birds known as the Corvida parvorder comprising many tropical and Australian passerines.

[9] Measuring 14 cm (5.5 in) in length, the azure-crested Flycatcher is sexually dimorphic.

The male has light blue crown with slate-blue upperparts, and white underparts.

[4] Unusually for the genus Myiagra the bill is bright orange instead of black.