Geodorcus novaezealandiae is a large flightless species of stag beetle in the family Lucanidae.

Like all other Geodorcus, they show sexual dimorphism: the male beetle has a much wider head and larger mandibles.

They have a dull to slightly glossy black exoskeleton with obvious raised ribs on the elytra.

[3] All Geodorcus species are protected under Schedule 7 of the 1953 Wildlife Act, making it an offense to possess, harm or sell these beetles.

[3] Under the New Zealand Threat Classification, it has a conservation status of "Naturally Uncommon" with the qualifier of "Range Restricted".