Common Yellowthroats are small songbirds that have olive backs, wings and tails, yellow throats and chests, and white bellies. Adult males have black face masks which stretch from the sides of the neck across the eyes and forehead, which are bordered above with white or gray. Females are similar in appearance, but have paler underparts and lack the black mask. Immature birds are similar in appearance to the adult female. First-year males have a faint black mask which darkens completely by spring.
There are 13 races of this bird. These races differ mainly in the males' facial patterns and the brightness of the yellow underparts. The southwestern forms of this bird are the brightest and the yellowest below.