Described by John Gould in 1841, it is a small parrot 22–24 cm (8+3⁄4–9+1⁄2 in) long and weighing 50–60 g (1+3⁄4–2 oz) with predominantly olive-brown upperparts and more yellowish underparts.

Gilbert stated that at the time of English colonisation the species was common on cliff faces on offshore islands, including Rottnest, near the western port of Fremantle, the nests in almost inaccessible locations.

The biologist Donald Brightsmith has proposed that several lineages of parrots and trogons switched to nesting in burrows to avoid tree-living mammalian predators that evolved and proliferated in the late Oligocene to early Miocene (30–20 million years ago).

[12] "Rock parrot" has been designated as the official common name for the species by the International Ornithologists' Union (IOC).

The sexes are similar in appearance, with predominantly olive-brown upperparts including the head and neck, and more yellowish underparts.

In South Australia, it is found as far east as Lake Alexandrina and Goolwa, though is rare in the Fleurieu Peninsula.

[19] The rock parrot is almost always encountered within a few hundred metres of the coast down to the high-water mark, though may occasionally follow estuaries a few kilometres inland.

The preferred habitat is bare rocky ground or low coastal shrubland composed of plants such as pigface (Disphyma crassifolium clavellatum), saltbush (Atriplex) or nitre bush (Nitraria billardierei).

[18] Rock parrots are encountered in pairs or small groups, although they may congregate into larger flocks of up to 100 birds.

On the mainland, nesting has been reported at Point Malcolm near Israelite Bay and Margaret River in Western Australia.

[18] Rock parrots are monogamous, the breeding pairs maintaining fidelity throughout their lives, although an individual may seek a new mate if the previous one dies.

[21] The nesting site is under rocks or in crevices or burrows, which may be covered by plants such as pigface,[18] or heart-shaped noon flower (Aptenia cordifolia).

They may re-use burrows of wedge-tailed shearwaters (Ardenna pacifica) or white-faced storm petrels (Pelagodroma marina).

[15] Foraging takes place in the early morning and late afternoon, with a rest during the heat of the day.

Birds forage in pairs or small groups, though up to 200 individuals may gather at an abundant food or water source.

[21] They generally forage on the ground, and can be approached easily while feeding, moving a short distance behind a tussock or rock if observers come too close.

[18] Rock parrots eat seeds of several species of grass (Poaceae), including common wild oat (Avena fatua), wheat (Triticum aestivum), hare's tail (Lagurus ovatus), and Australian brome (Bromus arenarius), and rush (Cyperaceae), as well as shrubs and particularly succulent plants of the family Aizoaceae, such as pigface, and Carpobrotus rossii, and the introduced species Carpobrotus aequilaterus and Mesembryanthemum crystallinum.

Daisy species' seed consumed include coastal daisybush (Olearia axillaris), variable groundsel (Senecio pinnatifolius), and the introduced capeweed (Arctotheca calendula), South African beach daisy (Arctotheca populifolia) and prickly sow-thistle (Sonchus asper).

Brassicaceae include the native leafy peppercress (Lepidium foliosum) and introduced European searocket (Cakile maritima).

[21] The International Union for Conservation of Nature (IUCN) lists the rock parrot as a species of least concern, though the overall population is decreasing.

On a survey of the island in 1965, Western Australian biologist Glen Storr found it to have become rare and concluded this was due to young birds being taken for the pet trade.

[27] The parrot may become obese, unwell or infertile by overindulgence in sunflower seed, and aviculturists recommend reducing the availability of these in the aviary.