The long-tailed silky-flycatcher (Ptiliogonys caudatus) is a passerine bird that occurs only in the mountains of Costa Rica and western Panama, usually from 1,850 m altitude to the timberline.

It is a thrush-sized species, weighing about 37 g. The silky-flycatchers are related to waxwings, and like that group, they have soft silky plumage.

The habitat of this bird is mountain forests, where the breeding pair builds a neat cup of lichen 2 to 18 m above ground in a tree, sometimes in loose colonies.

The male long-tailed silky-flycatcher is 24 cm long and has a pale grey forehead.

The back, lower breast, and upper belly are blue-grey, and the flight feathers and long pointed tail are black.