Stanwellia pexa is a species of mygalomorph spider in the Pycnothelidae family. It is endemic to Australia. It was described in 1930 by Australian arachnologist Vernon Victor Hickman.
The species occurs in Tasmania, including Bass Strait islands, along coastlines in supralittoral habitats. The type locality is Prince of Wales Bay, Derwent Park, Hobart.
The spiders are fossorial, terrestrial predators.