The Short-tailed Finch (Idiopsar brachyurus) is a species of bird traditionally placed in the Emberizidae family, but it appears to be related to the sierra-finches Phrygilus of the tanager family Thraupidae and it may eventually join them there. It is the only member of its genus, Idiopsar.

It is found in Argentina, Bolivia, and Peru. Its natural habitat is subtropical or tropical high-altitude grassland.