The cerulean flycatcher (Eutrichomyias rowleyi) is a medium-sized (up to 18 cm long), blue passerine with bright cerulean blue plumage, a bare white orbital ring, dark brown iris, bluish black bill and pale blue-grey below.

The scientific name commemorates the British explorer and ornithologist George Dawson Rowley.

Although initially classified in Monarchidae, a 2017 study involving sequencing of DNA from the type specimen found that it was a member of the fantail family Rhipiduridae, being classified in the basal subfamily Lamproliinae (sometimes considered a distinct family) along with Chaetorhynchus and Lamprolia.

Previously known only from a single specimen collected in 1873, this rare bird was rediscovered in October 1998 around forested valleys of Mount Sahendaruman in southern Sangihe.

Due to ongoing habitat loss, a small population size, and limited range, the cerulean flycatcher is evaluated as Critically Endangered on the IUCN Red List of Threatened Species.