The tyrant flycatchers (Tyrannidae) are a family of passerine birds which occur throughout North and South America. They are considered the largest family of birds known to exist in the world, with more than 400 species. They are the most diverse avian family in every country in the Americas, except for the United States and Canada. The members vary greatly in shape, patterns, size and colors. Some tyrant flycatchers may superficially resemble the Old World flycatchers, which they are named after but are not closely related to. They are members of suborder Tyranni (suboscines), which do not have the sophisticated vocal capabilities of most other songbirds.

A number of species previously included in this family are now placed in the family Tityridae (see Systematics). Sibley and Alquist in their 1990 bird taxonomy had the genera Mionectes, Leptopogon, Pseudotriccus, Poecilotriccus, Taenotriccus, Hemitriccus, Todirostrum and Corythopis as a separate family Pipromorphidae, but although it is still thought that these genera are basal to most of the family, they are not each other's closest relatives.