Geosesarma larsi is a species of small land-living highland crab found in western Sarawak, Borneo. Adults have a carapace width of 12–15 mm and are of a purplish-red colour, which distinguishes them from other Geosesarma species in Borneo. The species is threatened by the loss of their small habitat.^[1][2]

Geosesarma larsi is named after the German photographer and naturalist Lars Fehlandt, who discovered this species during an expedition in December 2016.^[1]