The Violaceous Euphonia is about 11.4 cm long. Males have blue-black backs and wings, yellow on the front of the head and underparts; females are greenish yellow above with dull yellow underparts.
Adults are about 11.4 cm long and weigh about 14 g. Males have yellow from the bill to the crown, a yellow throat, breast and belly, and blue-black back and wings. Females have greenish-yellow backs and wings and dull yellow underparts.
It forages in treetops, often in small flocks with other tanagers, eating soft berries, fleshy fruits, nectar, and insects. It builds a ball-shaped nest with a side entrance; the female incubates, and both sexes feed the young.
An extinction-risk assessment has not been added yet.