The new genus, Cameronia Kantvilas, is described and illustrated. It is characterized by a crustose thallus, a chlorococcalean photobiont, deeply immersed perithecioid ascomata, four-spored asci with an intensely hemiamyloid outer wall and non-amyloid, well-developed tholus, and hyaline, muriform ascospores. The taxonomic position of the new genus is uncertain although a relationship with the Ostropomycetidae is likely. Two species, both endemic to the highlands of Tasmania, are described: C. pertusarioides Kantvilas, which is one of the most common lichens on dolerite in alpine Tasmania, and C. tecta Kantvilas, which is confined to metamorphosed sediments.