Typhinellus insolitus is a species of sea snail, a marine gastropod mollusk in the family Muricidae, the murex snails or rock snails. The species is known only from its holotype collected off New Caledonia.
The shell is medium-sized for the subgenus, reaching a length of 16.9 mm at maturity. The spire is high, consisting of five teleoconch whorls; the protoconch is broken in the holotype. Sutures are impressed. Each whorl bears four varices. On the last teleoconch whorl, the varices are sharp.
Loyalty Islands, New Caledonia. The holotype was collected dead at a depth of approximately 373 m.
No information is available on the ecology or life habits of this species. No additional material has been collected since the original description.
The specific name insolitus is derived from Latin, meaning "unusual", referring to the unusual shape of the shell.