Cantuaria insulana is a species of trapdoor spider endemic to New Zealand.
This species was described in 1968 by Ray Forster from female specimens collected in Marlborough Sounds.
The female is recorded at 17.3mm in length. The carapace and legs are orange brown. The abdomen is cream with dorsal bands.
This species is only known from D'Urville Island in New Zealand.
Under the New Zealand Threat Classification System, this species is listed as Naturally Uncommon with the qualifiers of "Island Endemic" and "One Location".