Sexually mature males are olive green above and white below with faint yellow flanks.

The crown and upper half of the head is black with a partial white eye ring and lores.

Females are duller in color than males and have a slate-gray crown and underparts washed with greenish yellow.

Territories are sometimes located on steep slopes, where trees are often clumped and intermediate in height.

On level terrain, the preferred black-capped vireo habitat is a mixture of shrubs and smaller trees that average from 8–10 ft high (2.5-3.5 m).

[6] In Oklahoma, the black-capped vireo is found only in Blaine, Cleveland, Cotton and Comanche Counties.

[7] The black-capped vireo is threatened by brown-headed cowbird (Molothrus ater) brood parasitism, human disturbance, loss of habitat to urbanization, fire exclusion, livestock grazing,[8] and brush control.