In 1760 the French zoologist Mathurin Jacques Brisson included a description of the yellow-faced grassquit in his Ornithologie based on a specimen collected in Saint-Domingue (now Haiti).

[2] Although Brisson coined Latin names, these do not conform to the binomial system and are not recognised by the International Commission on Zoological Nomenclature.

[3] When in 1766 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the twelfth edition he added 240 species that had been previously described by Brisson.

Linnaeus included a terse description, coined the binomial name Emberiza olivacea and cited Brisson's work.

A molecular phylogenetic study published in 2014 found that the genus was non-monophyletic and in the subsequent rearrangement four species were moved to other genera.

The adult male has an olive-green back, and its face and breast are black apart from a bright yellow throat, supercilia, and lower eyelid spot.

[11][12][13] The yellow-faced grassquit is a common to abundant resident in lowlands and foothills up to 2,300 m (7,500 ft) altitude in semi-open areas such as roadsides, pasture, weedy fields and low scrub.

It avoids dry grassland and other very low growth, but will readily utilize neglected gardens where lawn grass has grown high.

During courtship, the male vibrates his wings as he sings his subdued song, sitting only 1–2 in (2.5–5.1 cm) away so the female can properly hear him.