Cadmus colossus, or Cadmus (Brachycaulus) colossus, is a species of beetle in the subfamily, Cryptocephalinae, or case-bearing leaf beetles, and the subgenus, Brachycaulus.

[1] It was first described by Félicien Chapuis in 1875,[1][2] from a male specimen collected at Port Denison.

[2] It is native to Australia,[3] being found in New South Wales and Queensland.

[1] The taxonomic reasoning for the subgeneric arrangement (accepted by the Australian Faunal Directory)[4] is given in Mathews and Reid (2002).

This Cryptocephalinae article is a stub.