It has mostly smooth bluish grey or white bark, lance-shaped to curved adult leaves, flower buds arranged in groups of seven, white flowers and cup-shaped, bell-shaped or conical fruit.Eucalyptus benthamii is a tree that grows to a height of 35 or 40 metres (115 or 131 ft) with a trunk diameter attaining 1.5 metres (4.9 ft) and forms a lignotuber.

[9] Eucalyptus benthamii was first formally described by Joseph Maiden and Richard Hind Cambage in 1915 from a specimen collected "from the banks of the Nepean River near Cobbity".

[11][12] Maiden and Cambage did not give a reason for the specific epithet (benthamii) but it is assumed to honour George Bentham.

[6] Camden white gum grows on alluvial plains on sand or loam over clay along the Nepean River and its tributaries, in tall open forest, where it either forms a pure stand or is found with other eucalypts such as mountain blue gum (E. deanei) and river peppermint (E.

It is known from two main populations, one near the Kedumba River in the Blue Mountains National Park, the other at Bents Basin State Recreation Area south of Wallacia.