Reig's tuco-tuco (Ctenomys osvaldoreigi) is a species of rodent in the family Ctenomyidae. It is endemic to central Argentina, where it is known only from a grassland location in Cordoba Province at an elevation above 2000 m in the Sierras Grandes. The species is threatened by disruption of its habitat by fire and sheep grazing. It is named after Argentine biologist Osvaldo Reig (1929–1992).