Isoplectron armatum is a species of tokoriro (cave wētā) that is endemic to New Zealand.

The name "armatum" is from the latin 'armed' (equipped with weapons) and refers to the conspicuous spine under the hind femur of adult males.

In 1937 Heinrich Hugo Karny described Isoplectron aciculatum from a male specimen from North Island New Zealand.

[2] The body is coloured light rusty brown, darkly marbled dorsally.

[2] During the day this species can be found hiding under tree bark or inside artificial refugia, often in groups of up to ten individuals.