The leaves are linear and divide into 3-5 narrow lobes 2.5–5 cm (0.98–1.97 in) long on slightly intersecting branchlets that are smooth and rusty coloured when young.

The perianth is white with a brownish limb, the inside is smooth and the outside covered in flattened dense silky hairs.

Flowering occurs in spring and the dry fruit is about 12 mm (0.47 in) long and densely covered in silky hairs.

[4][6] This species has a restricted distribution, it grows in sandy, gravelly loams in dry sclerophyll forest, mostly on ridge tops, occasionally on slopes, between Dapto, Robertson and Berrima in New South Wales.

[5] Grevillea raybrownii is listed as a "vulnerable species" under the New South Wales Government Biodiversity Conservation Act 2016.