Buelliastrum is a fungal genus of uncertain familial and ordinal placement in the class Lecanoromycetes. The genus was circumscribed by the lichenologist Alexander Zahlbruckner in 1930 to contain two little-known species found in China. He did not indicate a type species for the genus. In his work (), Zahlbruckner described more than 280 new taxa, mostly collected from the greater Tibetan region of North Yunnan and South west Sichuan.