The red-billed parrot is long and weighs about . All of the subspecies have the eponymous red bill. Adults of the
nominate subspecies P. s. sordidus have a dull green head whose feathers have dull blue edges; their eye is surrounded by bare grayish skin. Their back, wings, and inner tail feathers are olive green; their outer tail feathers are blue. Their upper breast is dull blue that becomes buff-olive with a pink tinge on the belly. Their undertail
coverts are red. Immature birds have a green head and breast and yellowish green undertail coverts. Subspecies
P. s. antelius is paler than the nominate and has very little blue on the breast.
P. s. saturatus is darker than the nominate and
P. s. ponsi is darker than
saturatus. Subspecies
P. s. corallinus is larger and greener than the nominate, and its mantle and back have gray and blue tinges.
P. s. mindoensis is similar to
corallinus but somewhat yellower. ==Distribution and habitat==