Grevillea aspleniifolia is a spreading shrub that typically grows to 1–5 m (3 ft 3 in – 16 ft 5 in) high and up to 5 m (16 ft) wide. The leaves are linear to narrowly egg-shaped, 150–250 mm (5.9–9.8 in) long and 3–15 mm (0.12–0.59 in) wide with irregular serrations and a woolly-hairy lower surface, the edges turned down or rolled under. The flowers are arranged in toothbrush-like racemes along a rachis usually 30–50 mm (1.2–2.0 in) long, and are purplish with grey or white hairs. The pistil is mostly 15–25 mm (0.59–0.98 in) long and the style has a green tip. Flowering mainly occurs from July to November and the fruits is a hairy follicle 11–12 mm (0.43–0.47 in) long.^[4][5][6][7]

Grevillea aspleniifolia was first formally described in 1809 by Joseph Knight in On the cultivation of the plants belonging to the natural order of Proteeae.^[8][9] The specific epithet (aspleniifolia) means ''Asplenium-leaved".^[6]

This grevillea grows in woodland on sandstone or shale in the catchments of the Warragamba Dam and Woronora River, and near Bungonia Caves, in eastern New South Wales.^[5][4]

Grevillea aspleniifolia is reported to be a hardy, fast-growing plant that tolerates heavy soil as long as the soil is well-drained. A sunny position is preferred.^[6]

This species is listed as "Near Threatened" on the IUCN Red List of Threatened Species. It has a restricted distribution and a naturally severely fragmented population, where it occurs in several small, isolated subpopulations. Threats to this species include damage and/or grazing by introduced deer and changed fire regimes.^[1]