songbird family, order Passeriformes, consisting of the thrushes, bluebirds, robins, and other birds—about 305 species of the most renowned songbirds in the world, absent only from the polar regions and certain islands.

Members range in size from 11.5 to 33 centimetres (4.5 to 13 inches) long. They have slender bills and stout legs and feet, the lower leg smooth rather than scaly. Included here are such delightful songsters as the nightingale (Luscinia megarhychos), American robin (Turdus migratorius), and wood thrush (Hylocichla mustelina); as well as the bluebirds (Sialia) of poetry and the European blackbird (T. merula). Kittlitz's, or Bonin, thrush (Zoothera terrestris), last seen in 1828 on Peel Island, the Bonins (southeast of Japan) and the Raiatea thrush (T. ulietensis), not seen since 1774 on Raiatea, Society Islands (near Tahiti), are both extinct.

The Turdidae belongs to the songbird suborder (Passeres).