The bearded mountaineer (Oreonympha nobilis) is a species of hummingbird in the "coquettes", tribe Lesbiini of subfamily Lesbiinae.

[4][5] The ornithologist John Gould described the species in 1869, from a specimen collected by Henry Whitely at Tinta District, and placed it in its own genus Oreonympha.

[6] A study of mitochondrial DNA of hummingbirds shows it to be most closely related to the bearded helmetcrests (Oxypogon sp.)

[9][4][10] However, BirdLife International's Handbook of the Birds of the World (HBW) treats these taxa as separate species, the eastern and western mountaineers respectively.

Adult males of the nominate subspecies have a deep purplish blue forecrown and crown with a narrow black stripe in the middle.

The "western" subspecies O. n. albolimbata is found in Peru's departments of Huancavelica, Ayacucho, and Apurímac, in the drainages of the Mantaro, Pampas, and Chalhuanca rivers.

[11] The species inhabits dry Andean valleys characterized by rocky and scrubby hillsides and open woodland.

It occurs in a variety of native plant communities but also is regularly found in tree tobacco (Nicotiana) and Eucalyptus even along roads and in towns.