The Crowned Slaty Flycatcher (Griseotyrannus aurantioatrocristatus) is a species of bird in the Tyrannidae family, the tyrant flycatchers. It was formerly united in the genus Empidonomus with the Variegated Flycatcher, but is now considered the only species of Griseotyrannus. The name: Griseotyrannus aurantioatrocristatus means: "Gray-tyrannus orange-colored black-crested". It is found in Argentina, Bolivia, Brazil, Colombia, Ecuador, Paraguay, Peru, Uruguay, and Venezuela. Its natural habitats are subtropical or tropical dry forests and subtropical or tropical moist lowland forests.

The black-Crowned Slaty Flycatcher migrates into the mostly western and central Amazon Basin as a non-breeding resident, except in the southeast bordering the Cerrado and Pantanal, where it is resident in much of the western cerrado and southwards; the migration occurs during the austral winter.

A curious fact about this bird is that its binomial is the longest of any bird species, fifteen syllables when spoken aloud.