Endococcus is a genus of lichenicolous (lichen-dwelling) in the family Lichenotheliaceae. It has 44 species. The genus was circumscribed by the Finnish botanist William Nylander in 1855. Although at least one source places the genus in the Verrucariaceae, a 2016 study of the type species, Endococcus rugulosus, determined that it should instead be placed in the family Lichenotheliaceae of the order Dothideales; this classification echoes a placement proposed in 1979 by David Hawksworth.