The Cerro Negro Formation is a sedimentary formation of Ediacaran age in Buenos Aires Province, Argentina. The formation crops out along the Tandilia System, a chain of hills made up by of ancient rocks. Together with the formations of the underlying Sierra Bayas Group it is contains the oldest sedimentary formations in Argentina that have not been subject to significant metamorphism or deformation. In 2015 a complete revision of the formation was proposed.

Soft-bodied discoidal specimens resembling Aspidella are described from the formation, that has been estimated as not older than 565 Ma.

• Dyke swarms of Tandil and Azul
• Puncoviscana Formation
• Nama Group

• Arrouy, María Julia; Warren, Lucas V.; Quaglio, Fernanda; Poiré, Daniel G.; Guimarães Simões, Marcello; Boselli Rosa, Milena; Gómez Peral, Lucía E. (2016), "Ediacaran discs from South America: probable soft-bodied macrofossils unlock the paleogeography of the Clymene Ocean", Scientific Reports, 6: Article number 30590, Bibcode:2016NatSR...630590A, doi:10.1038/srep30590, PMC 4962044, PMID 27460966, retrieved 2019-02-12
• Arrouy, M. Julia; Poiré, Daniel G.; Gómez Peral, Lucía E.; Canalicchio, José María (2015), "Sedimentología y estratigrafía del Grupo La Providencia (nom. nov.): cubierta superior neoproterozoica, Sistema de Tandilia, Argentina" (PDF), Latin American Journal of Sedimentology and Basin Analysis, 22 (2): 171–189, retrieved 2019-02-12