[3][4] It is endemic to Borneo and is found in Sabah and central Sarawak (Malaysia), Brunei, and north-eastern Kalimantan (Indonesia).

[3] The specific name gauni honours Gaun Sureng, a collector for the Sarawak Museum and a companion to Robert F. Inger on field trips when this species was observed.

The legs have dark dorsal crossbars, and the anterior and posterior faces of thigh reddish orange.

[2] Leptomantis gauni occurs in primary and old secondary lowland and hilly rainforests[1][4] at elevations of 100–980 m (330–3,220 ft) above sea level.

The tadpoles live in riffles where they use their oral sucker to cling to rocks.