Grevillea australis is a densely-foliaged, erect to spreading or prostrate shrub that grows to a height of . Its leaves are simple, narrowly egg-shaped with the narrower end towards the base or linear, long and wide with the edges turned down or rolled under. The flowers are arranged in groups near the ends of braches along a rachis long, and are white or pale pink. The pistil is long and cream-coloured, the style is hooked near the tip, the ovary stalked and glabrous. Flowering mostly occurs from December to February and the fruit is a glabrous follicle.
