Olearia X macrodonta is a small sub-alpine evergreen tree endemic to New Zealand, from the plant family Asteraceae.

It is a hybrid derived from narrow-leaved Olearia ilicifolia, with which it shares several characteristics including largely undulating and serrated grey-green leaves and Olearia arborescens. These common characteristics mean the two species and the hybrid are often confused with one another. It is found from lowland to sub-alpine forests from the East Cape of the North Island of New Zealand southwards. It is found occasionally in the South Island and Stewart Island, usually where both parent species occur and at altitudes from 450 - 1,200 metres. In Taranaki, it is found on Mt Taranaki in the area of Holly Hut (named after this tree O. ilicifolia). Holly hut is a hut on the north side of Mt Taranaki by the Dome at the top of the Ahukawakawa swamp. Olearia X macrodonta is a shrub to spreading small tree that grows 1.5 - 6 metres tall. Its leaves are 5 - 10 centimetres long, 2.5 - 4 cm wide, with undulating and coarsely serrated margins, greyish green above. Its flowers are white with yellow centres and grow in large, rounded, much-branched corymbs.