Cerothallia yarraensis is a species of corticolous (bark-dwelling), crustose lichen in the family Teloschistaceae.

[2] Found in Australia, it was formally described as a new species in 2009 by lichenologists Sergey Kondratyuk and Ingvar Kärnefelt, as Caloplaca yarraensis.

[4] The lichen has a small, indistinct grey to dark grey thallus measuring 2–9 mm in diameter, raised apothecia, and a well-developed thalline exciple.

At the type locality, the lichen was found growing on twigs of the plant Halsarcia.

Cerothallia yarraensis occurs in a few localities in Western Australia, Tasmania, and Victoria.