The Araucaria tit-spinetail (Leptasthenura setaria) is a Near Threatened species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae.

It is a small-bodied, long-tailed furnariid with a short crest and a longish (for the genus) slightly decurved bill.

Their iris is brown or gray, their bill blackish with a paler base to the mandible, and their legs and feet grayish green.

[4][5] The Araucaria tit-spinetail is found in Brazil from far southern Minas Gerais and Rio de Janeiro states south into Rio Grande do Sol and west into northern Argentina's Misiones Province.

It inhabits Araucaria angustifolia trees in almost any landscape, be it forest, woodland, scattered groves, gardens, or plantations.

The Araucaria tit-spinetail's song is a "series (2-3 sec) of very high, thin notes changing in tempo between trill and rattle".

It has a small range, highly specialized habitat requirements, and an unknown population size that is believed to be decreasing.