Two new species of oribatid mites of the family Oppiidae (Oribatida, Oppioidea), belonging to the genera Lanceoppia and Rhinoppia, are described from Sphagnum magellanicum from a swamp in the vicinity of Punta Arenas in Chile. Lanceoppia (Bicristoppia) archicostulata n. sp. is morphologically similar to L. (Bicristoppia) bicristata Hammer, 1962(b), but differs by the well-developed transcostula, the presence of a median indentation on the rostrum and by setae la and lm being the longest of all notogastral setae. Rhinoppia (Rhinoppia) paraundulata n. sp. is morphologically similar to R. (Rhinoppia) undulata (Mahunka and Mahunka-Papp, 2010), but differs by the long notogastral setae, the presence of longitudinal ridges in the interbothridial region, five pairs of genital setae and by the interlamellar setae being distinctly longer than rostral and lamellar setae. An identification key to known species of Lanceoppia (Bicristoppia) is given.