The flowers are usually arranged on the ends of branches in groups of 12 to 16 on a peduncle up to 5 mm (0.20 in) long, and are red or deep reddish-pink, occasionally pink, the pistil 27–36 mm (1.1–1.4 in) long.

Flowering mainly occurs from August to November and the fruit is an elliptic follicle 10–15 mm (0.39–0.59 in) long.

[2][3] Grevillea oleoides was first formally described in 1827 by Josef August Schultes and Julius Hermann Schultes in their book Mantissa in volumen primum [-tertium] :Systematis vegetabilium caroli a Linné from an unpublished description by Franz Sieber.

[4][5] The specific epithet (oleoides), means similar to the European olive, Olea europaea.

[6] Red spider flower mainly occurs in the Sydney basin from Botany Bay and the Georges River to the northern Illawarra region, where it grows in dry sclerophyll woodland or heathland, often in moist locations near creeks or swamps.