Castanopsis pedunculata is a tree in the family Fagaceae. The specific epithet pedunculata means 'having a '.
Castanopsis pedunculata grows as a tree up to 25m (82feet) tall with a trunk diameter of up to 40cm (20inches). The brown bark is flaky to . The leaves measure up to 14cm (06inches) long. Its nuts measure up to 21NaN1 long.
Castanopsis pedunculata is endemic to Borneo. Its habitat is lowland dipterocarp forests up to 300m (1,000feet) elevation.
Castanopsis pedunculata has been assessed as near threatened on the IUCN Red List. The species occurs in a number protected areas, where its population is stable. Outside of these areas, the species is threatened by land conversion for agriculture.