Pseudotyrannochthonius gigas is a species of pseudoscorpion in the Pseudotyrannochthoniidae family. It is endemic to Australia. It was described in 1969 by Austrian arachnologist Max Beier.
The species occurs in the Western District of Victoria. The type locality is Harman One Cave, Byaduk.
The pseudoscorpions are cave-dwelling terrestrial predators.