Caloplaca adnexa is a species of saxicolous (rock-dwelling), crustose lichen in the family Teloschistaceae. It was formally described as a new species in 1977 by Czech lichenologist Antonín Vězda. The type specimen was collected from the mountain Popova Šapka in the former Yugoslavia (now North Macedonia), at an altitude of 2000m (7,000feet). In addition to Europe, it is also found in North America.