The Scottish crossbill is a small passerine bird in the finch family Fringillidae. It is endemic to the Caledonian Forests of Scotland, and is the only terrestrial vertebrate species endemic to the United Kingdom. The Scottish crossbill was confirmed as a unique species in August 2006, on the basis of having a distinctive bird song.

The Caledonian Forest is the ancient (old-growth) temperate forest of Scotland. The forest today is a reduced-extent version of the pre-human-settlement forest, existing in several dozen remnant areas.