Viridothelium is a genus of lichen-forming fungi in the family Trypetheliaceae. It has 11 species. The genus was circumscribed by Robert Lücking Matthew Nelsen, and André Aptroot in 2016, with Viridothelium virens assigned as the type species. Lichens in this genus were previously assigned to genus Trypethelium, as part of the Trypethelium virens clade.