Phormosoma bursarium is a species of sea urchin in the order Echinothurioida, which is found at depths between 170 metre to 2340 metre.
The species was first described in 1881 by Alexander Agassiz.
In Australia it is found in waters off Batemans Bay, NSW, and off Port Hedland, WA. It is a benthic species, found in both temperate and tropical waters.