The yellow-billed amazon is 28 cm (11 in) long. Its plumage is mostly green with pink over the throat, upper breast and sides of neck, and blue in the larger wing feathers. Feathers over the ears are dark blue-green. The bare white eye-rings are surrounded by a narrow rim of white plumage, which continues as a narrow band of white over the forehead. Plumage over the lores is pale blue and the fore-crown is blue. A barred appearance over the back and sides of neck arises from the green feathers having black tips and edges. The tail feathers are green with red bases. Its beak is yellow, its irises are brown, and its legs are pink. The adult male and female are identical in external appearance. Juveniles have grey on the upper mandible and are otherwise similar to adults.