Eucalyptus nicholii is a tree that typically grows to a height of 15–18 m (49–59 ft) and forms a lignotuber.

The specific epithet honours Maiden's private secretary and "Chief Clerk, Botanic Gardens", Richard Nicol.

[5] Its distribution is limited to the Northern Tablelands, New South Wales, particularly in the Walcha to Tenterfield, area and to the east.

The main threats to the species are land clearing and habitat fragmentation, inappropriate fire regimes, grazing by livestock and feral goats, road maintenance and collection of firewood.

[2][9] This tree is very widely planted as an ornamental in southeastern Australia, the fine, dense foliage being particularly attractive.