The Chestnut-bellied Seed-finch (Oryzoborus angolensis) is a species of bird in the Thraupidae family, but was until recently placed in Emberizidae. It is found widely in shrubby and grassy areas in tropical and subtropical South America, but is replaced west of the Andes (and in Central America) by the closely related Thick-billed Seed-finch, in which the male lacks the chestnut belly of the male Chestnut-bellied Seed-finch. The two have often been considered conspecific as the Lesser Seed-finch.