Several other genera were invalidly named Leiosoma. The mite genus of Nicolet (1855) is now Liacarus. The echinoid genus of Cotteau (1860) is now Trochalosoma. The lepidopteran genus of Felder & Rogenhofer (1874) is now Erocha. The millipede genus of Silvestri (1897) is now Catharosoma.
Leiosoma is a genus of weevils. It can be found in mountain-forest and alpine habitats in the western Palearctic realm. These weevils feed on plants of the families Ranunculaceae and Violaceae.