Castanopsis pedunculata is a tree in the family Fagaceae. The specific epithet pedunculata means 'having a '.
Castanopsis pedunculata grows up to tall with a trunk diameter of up to . The brown bark is flaky to . The leaves measure up to long. Its nuts measure up to long.
Castanopsis pedunculata is endemic to Borneo. Its habitat is lowland dipterocarp forests up to 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.