Xanthoparmelia crassilobata is a species of terricolous (soil-dwelling), foliose lichen in the family Parmeliaceae. Found in South Africa, it was formally described as a new species in 1986 by the American lichenologist Mason Hale. The type specimen was collected from Cape Province at an elevation of , where it was found growing on soil on flat dolerite outcrops in a pasture. The lichen has a leathery and bright yellowish-green thallus, measuring in diameter, that grows with a loosely attachment to its of soil and loose pebbles. It contains salazinic acid and usnic acid.