The violaceous euphonia was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae based on a specimen in the collection of Adolf Frederick of Sweden.

[6] Three subspecies are recognised:[6] Adult violaceous euphonias are 11.4 cm long and weigh 14 g. The male has glossy blue-black upperparts and a deep golden yellow forehead and underparts.

The ball nest is built on a bank, tree stump or cavity and the normal clutch is four, sometimes three, red-blotched white eggs, which are incubated by the female.

[7] The violaceous euphonia's song is a varied mix of musical notes, squeaks, chattering and imitation.

Members of the genus Euphonia are prized as cage birds and several are threatened by trapping, but this species benefits from its relatively inaccessible habitat.