The sexes have similar plumage, while females and younger birds are generally duller with occasional spots of red.

Found in woodland and open savanna country, the northern rosella is predominantly herbivorous, consuming seeds, particularly of grasses and eucalypts, as well as flowers and berries, but it may also eat insects.

Although uncommon, the northern rosella is rated as least concern on the International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species.

[2] The description was based on an illustration by Ferdinand Bauer from a specimen collected by Robert Brown in February 1803, during Matthew Flinders' voyage around the Australian coastline.

"[7] Gregory Mathews described the subspecies P. venustus hillii in 1910, collected by G.F. Hill from Napier Broome Bay in Western Australia.

[9] Animal taxonomist Arthur Cain treated the subspecies as synonymous to the nominate, as the only difference of which he knew was the colour of the cheeks, but conceded further evidence could prove them distinct.

[9] A subspecies, P. venustus melvillensis from Melville Island, was described by Mathews in 1912, noting it to have blacker plumage on its back.

[3] "Northern rosella" has been designated the official English name by the International Ornithologists' Union (IOC).

A 1987 genetic study on mitochondrial DNA by Ovenden and colleagues found that the northern rosella was the earliest offshoot (basal) of a lineage that gave rise to the other white-cheeked forms.

[19] The adult bird has a black forehead, crown, lores, ear coverts, upper neck and nape, a whitish throat and large cheek-patches, which are mainly white with violet lower borders in the nominate subspecies,[20] and more blue with a narrow white upper segment in subspecies hillii.

The feathers of the lower neck, mantle and scapulars are black narrowly fringed with yellow, giving a scalloped appearance, while the feathers of the back, rump, upper tail coverts and underparts are pale yellow with black borders and concealed grey bases.

In Western Australia, it is found across the Kimberley south to the 18th parallel, around Derby, Windjana Gorge National Park, the northern Wunaamin Miliwundi Ranges, Springvale Station and Warmun, with vagrants reported at Halls Creek and Fitzroy Crossing.

More specific habitats include vegetation along small creeks and gorges, sandstone outcrops and escarpments, as well as some forested offshore islands.

[15] The northern rosella feeds on the ground in grassy glades in woodlands and on roadsides and riverbanks, as well as in the canopy of trees.

[25] The northern rosella is listed as being a species of least concern by the International Union for Conservation of Nature (IUCN), on account of its large range and stable population, with no evidence of any significant decline.

[21] Grazing by livestock and frequent burning of grassy woodland may have a negative impact on northern rosella numbers.