The peg-billed finch (Acanthidops bairdi) is a passerine bird endemic to the highlands of Costa Rica and western Panama.

The peg-billed finch was formally described in 1882 by the American ornithologist Robert Ridgway from a specimen collected near the Irazú Volcano in Costa Rica.

This is an uncommon bird at the edges and clearings of mountain forests, and in scrubby second growth, bamboo clumps, and bushy pastures from 1500 m altitude to the timberline.

Its numbers have reported to be high when the bamboo is flowering on favoured sites such as Cerro de la Muerte.

The finch is seen singly, in pairs, family groups or in mixed-species feeding flocks with other small birds such as warblers.