The berylline hummingbird (Saucerottia beryllina) is a species of hummingbird in the "emeralds", tribe Trochilini of subfamily Trochilinae. It is found in El Salvador, Guatemala, Honduras, Mexico, and the United States.
The berylline hummingbird is 8 to 10 cm (3.1 to 3.9 in) long.The bills of males of all subspecies have a black maxilla and a pinkish mandible with a black outer half. Adult males of the nominate subspecies S. b. beryllina have a bronze-green to coppery head, back and rump. Their uppertail coverts and tail are coppery to rufous. The bases of their primaries and secondaries are chestnut and show as a patch on the closed wing. Their underparts are glittering golden green. Adult nominate females are very similar to males, but with a paler and more grayish throat and belly. Their bills are entirely black. Juveniles are similar to females but with a grayish cinnamon belly.