Xanthoparmelia somervilleae is a species of saxicolous (rock-dwelling), foliose lichen in the family Parmeliaceae.

The type specimen was collected by the authors from Gunners Quoin (Tasmania), where it was found in an open Eucalyptus woodland growing on dolerite rocks.

The species epithet honours Janet Sommerville (1887–1969), who was a Tasmanian botanist, historian, and naturalist.

[2] Xanthoparmelia somervilleae occurs in scattered locations throughout Tasmania, growing on rocks in dry, sun-exposed sclerophyll forests.

It often grows in association with other lichens, including Paraporpidia leptocarpa, Ramboldia petraeoides, Rhizocarpon geographicum, Tephromela atra, and other Xanthoparmelia species, such as X. dichotoma, X. neotinctina, X. subprolixa, X. tasmanica, and X. vicaria.