The buff-throated saltator is on average 20 cm (7.9 in) long and weighs 42–52 g (1.5–1.8 oz). The adult has a slate-grey head with a white supercilium and a greenish crown. The upperparts are olive green, the underparts are grey becoming buff on the lower belly, and the throat is buff, edged with black. The thick convex bill and legs are black. Young birds are duller, and have a white-mottled blackish throat and breast, and brown markings on the lower underparts.