Although almost 50 species of Galumnidae (Oribatida) have been recorded in Japan, more species remain undiscovered. In the present work, we propose two new species from southern Japan, Trichogalumna boninensis sp. nov. and T. ohkuboi sp. nov., and provide an additional description of T. imperfecta Ohkubo, 1984. Trichogalumna boninensis sp. nov. can be distinguished from other closely related species by the smaller body size, and the large granular ornamentation along the hinges of the pteromorphs. Trichogalumna ohkuboi sp. nov. can be distinguished from other closely related species by the absence of granular ornamentation on the proximal margin of the dorsal surface of the pteromorph, the striated genital plates, the absence of granular ornamentation on the humeral region of the notogaster, the short lamellar and interlamellar setae, the distantly located porose areas of A₁ and A₂, and the different number of epimeral setae. Furthermore, we present data on habitat ecology and biogeography of Japanese species of Trichogalumna, and a key is provided for identification of all species in the world.