Eucalyptus cullenii, commonly known as Cullen's ironbark,[2] is a species of small to medium-sized tree that is endemic to Queensland.

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

It has thick, rough, dark grey or black, deeply and widely furrowed ironbark on its trunk and branches.

[4][5] The specific epithet (cullenii) honours William Portus Cullen, a barrister and later Chief Justice of New South Wales.

[2][4] Cullen's ironbark grows in red podsols and shallow stony soil in hilly or undulating woodland on the northern and eastern parts of the Cape York Peninsula.