The Green-crowned Brilliant (Heliodoxa jacula) is a large robust hummingbird that is a resident breeder in the highlands from Costa Rica to western Ecuador.

This hummingbird inhabits wet mountain forests including edges, gaps and tall second growth. It occurs typically between 700 m and 2000 m in altitude, mainly on the Caribbean slopes.

The nest is a bulky cup of plant fibres and scales of tree ferns saddled on a thin downsloping branch. The female alone incubates the two white 16.5 mm by 11 mm eggs Sánchez et al.

The male Green-crowned Brilliant is 13 cm long and weighs 9.5 g. It is mainly bronze-green with a glittering green crown, forehead, throat and breast. It has a white spot behind the eye, a small violet throat patch, white thighs, and a deeply forked blue-black tail.

The female is 12 cm long and weighs 8 g. She differs from the male in that she has green-spotted white underparts, a white spot behind the eye and a white stripe below the eye, and a white-cornered shallowly-forked black tail.. Young birds resemble the adult of the same sex, but are duller, bronze-tinged below and have buff throats.

Female.

The Green-crowned Brilliant has a loud squeaky kyew call.

This hummingbird feeds at the large inflorescences of Marcgravia vines, which the male will sometimes defend. It will also feed at Heliconia and other large flowers. Unlike many hummingbirds, the Green-crowned Brilliant almost always perches to feed.