Ceramothyrium is a genus of ascomycete fungi in the family Chaetothyriaceae.
In 2024, Ceramothyrium ryukyuense was described from Okinawa Island, Japan, as the first lichen-forming member of Ceramothyrium â and the first confirmed lichenised lineage in the family Chaetothyriaceae â forming a thin, leaf-dwelling thallus with a Trentepohliales green-algal partner.