Tyrannochthonius souchomalus is a species of pseudoscorpion in the Chthoniidae family. It is endemic to Australia. It was described in 2008 by Australian arachnologists Karen Edward and Mark Harvey.
The species occurs in the Murchison bioregion of Mid West Western Australia. The type locality is a borehole on Austin Downs Station.
The arachnids are cave-dwelling, terrestrial predators.