Nestotus stenophyllus is a species of flowering plant in the family Asteraceae known by the common name narrowleaf mock goldenweed.

It is native to the western United States, especially the inland Pacific Northwest and northern Great Basin, where it grows in sagebrush habitat usually in rocky soil.

The inflorescence is a solitary flower head atop an erect densely to sparsely wooly peduncle that emerges from the tip of the leafy stem.

The involucre (flower bract) is 5 to 9 mm long and consists of many lanceolate lobes with pointed tips.

The bracts often appear to have a fringe of long hairs near the top of each lobe, which is actually attached to the base of the florets and will form part of the seed pappus.