Acanthothecis roseola is a species of corticolous (bark-dwelling) lichen in the family Graphidaceae.

Found in Brazil, it was formally described as a new species in 2022 by Shirley Cunha Feuerstein.

The type specimen was collected from the Parque Estadual do Papagaio Charão (Sarandi, Rio Grande do Sul).

The lichen has a whitish to greenish, cracked thallus with a black prothallus.

The specific epithet roseola refers to the pinkish-coloured margins of the ascomata.