It is a tree with paripinnate leaves with 4 to 14 elliptic to egg-shaped leaflets with domatia along the midrib, separate male and female flowers arranged in panicles, the fruit a brown capsule containing a reddish-brown seed with a brown aril.

Cupaniopsis dallachyi is tree that typically grows to a height of up to 25 m (82 ft), its branchlets sometimes covered with fine, soft, rust-coloured hairs.

[2][3] Cupaniopsis dallachyi was first formally described in 1985 by Sally T. Reynolds in the Flora of Australia from specimens collected near Jaggan in 1980.

[4] The specific epithet (dallachyi) honours John Dallachy.

[2] This species of Cupaniopsis grows in rainforest from near Daintree to south of Ravenshoe in north Queensland, at altitudes between 150–750 m (490–2,460 ft).