The Ayacucho thistletail (Asthenes ayacuchensis) is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae.

Their back and rump are brownish and their wings dark brown with rufous edges to the feathers.

Their tail is a paler but more rufescent brown than the back; it is long and deeply forked with few barbs at the feather ends that give a ragged appearance.

It primarily inhabits elfin forest and Polylepis woodlands in the tree line ecotone.

The Ayacucho thistletail's primary song is "a rapid, high-pitched, even trill lasting two seconds in duration, delivered at a steady frequency".

[1] Its total range is "perhaps just 500 km2 [190 mi2], within which elfin forest habitats are fragmented and degraded by anthropogenic disturbance.