The olive spinetail (Cranioleuca obsoleta) is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae.

Their tail is chestnut-rufous; the feathers are graduated and lack barbs at the end giving a spiky appearance.

Their throat is whitish, their breast buffy brownish, their belly pale olive-buff, and their flanks and undertail coverts somewhat darker.

[5][6][7] The olive spinetail is found from southern São Paulo state in southeastern Brazil south through eastern Paraguay into northeastern Argentina as far as northern Corrientes Province.

It hitches and climbs along trunks and small branches, mostly in the forest's mid-storey but occasionally to its canopy.

[5][6] The olive spinetail's breeding season is probably the austral spring and summer; eggs have been noted in October.

However, it has a "relatively small range, within which extensive deforestation has dramatically reduced [the] total area of its habitat".