The black-and-rufous warbling finch (Poospiza nigrorufa) is a species of bird in the tanager family Thraupidae. It is found in Argentina, Bolivia, Brazil, Paraguay, and Uruguay. Its natural habitats are subtropical or tropical dry shrubland, subtropical or tropical moist shrubland, swamps, and heavily degraded former forest. This species was formerly considered conspecific with the black-and-chestnut warbling finch (Poospiza whitii). The taxa were split based on molecular genetic and phenotypic data.