The gray catbird, also spelled grey catbird, is a medium-sized North American and Central American perching bird of the mimid family. It is the only member of the "catbird" genus Dumetella. Like the black catbird, it is among the basal lineages of the Mimidae, probably a closer relative of the Caribbean thrasher and trembler assemblage than of the mockingbirds and Toxostoma thrashers. In some areas it is known as the slate-colored mockingbird.

The mimids are the New World family of passerine birds, Mimidae, that includes thrashers, mockingbirds, tremblers, and the New World catbirds. As their name suggests, these birds are notable for their vocalization, especially some species' remarkable ability to mimic a wide variety of birds and other sounds heard outdoors. They are commonly referred to as mimic thrushes but are not, in fact, thrushes.