The adult long-billed corella measures from 38 to 41 cm in length, has a wingspan around 80–90 cm, and averages 567 g in weight. It has a long, bone-coloured beak, and a rim of featherless, bluish skin around the eyes. The plumage is predominantly white with reddish feathers around the eyes and lores. The underside of the wings and tail feathers are tinged with yellow.