Tyrannochthonius norfolkensis is a species of pseudoscorpion in the Chthoniidae family. It was described in 1976 by Austrian arachnologist Max Beier.
The body length of males is 1.2 mm; that of females is 1.3-1.55 mm. The colour is brown.
The species occurs in New Zealand as well as on Norfolk Island, an Australian territory in the south-west Pacific Ocean, where it inhabits plant litter. The type locality is Mount Pitt on Norfolk Island.
The arachnids are terrestrial predators.