Idiosoma occidentale is a species of mygalomorph spider in the Idiopidae family. It is endemic to Australia. It was described in 1903 by British arachnologist Henry Roughton Hogg.
The species occurs in north-west Western Australia. The type locality is Roebourne in the Pilbara region, some 1,560 km north of Perth.
The spiders are fossorial, terrestrial predators.