This paper describes Plantago corvensis, a new species endemic to rocky cliffs in Serra do Corvo Branco, southern Santa Catarina, southern Brazil. The new species is morphologically very distinct from other Plantago species native to South America because of the distinctly petiolate ovate leaves, the retrorse trichomes on scape, and the 4-seeded fruits. Plantago corvensis is known from only one locality and, according to the IUCN criteria, is considered critically endangered (CR).