Banksia arctotidis is a prostrate shrub that typically grows to a height of, width of and has a short underground stem. The leaves are linear, long and wide, pinnately divided to the midrib with between 25 and 45 sharply pointed lobes on each side. The flower spikes are surrounded by hairy thread-like, egg-shaped and oblong bracts and are composed of between 75 and 100 individual flowers. The perianth is long and yellow cream-coloured or yellowish brown. Flowering occurs between September and October and the fruit is a partly hairy, egg-shaped follicle long.