Xanthomendoza kashiwadanii is a species of saxicolous (rock-dwelling), crustose lichen in the family Teloschistaceae. Found in South America, it was formally described as a new species in 2009 by lichenologists Sergey Kondratyuk and Ingvar Kärnefelt. The type specimen was collected from (Magallanes Region, Chile), at an altitude of , where it was found on a dry rocky cliff growing on rocks. The species epithet honours Japanese lichenologist Hiroyuki Kashiwadani, who collected the type. Xanthomendoza kashiwadanii is only known to occur in a few localities in Argentina and Chile, where it grows on volcanic and basalt rock.