The bluebirds are a North American group of medium-sized, mostly insectivorous or omnivorous birds in the order of Passerines in the genus Sialia of the thrush family (Turdidae). Bluebirds are one of the few thrush genera in the Americas.

The thrushes are a passerine bird family, Turdidae, with a worldwide distribution. The family was once much larger before biologists reclassified the former subfamily Saxicolinae, which includes the chats and European robins, as Old World flycatchers. Thrushes are small to medium-sized ground living birds that feed on insects, other invertebrates and fruit. Some unrelated species around the world have been named after thrushes due to their similarity to birds in this family.