Tree to 16 m high. Bark rough, fibrous, red-brown on trunk and larger branches, then smooth and brown-red or grey above, or sometimes rough throughout. Juvenile leaves opposite, sessile or shortly petiolate, amplexicaul, orbicular to cordate, glaucous, slightly discolorous. Intermediate leaves opposite, sessile or shortly petiolate, sometimes amplexicaul, ± cordate or broadly ovate, glaucous or almost green. Juvenile or intermediate leaves usually persist on adult trees. Adult leaves alternate, broadly lanceolate, acuminate, thick; lamina 7.5–11.5 cm long, 1.5–2.5 cm wide, glaucous, concolorous; lateral veins faint, at 30°–45°; intramarginal vein up to 2 mm from margin; petiole flattened, 5–11 mm long. Umbels 3-flowered; peduncle terete, 2–6 mm long; pedicels absent. Buds fusiform, glaucous; operculum conical, 2–3 mm long, 4–5 mm wide; hypanthium obconical, 3–4 mm long, 4–5 mm wide. Fruits obconical to hemispherical, 5–8 mm long, 5–9 mm wide; disc broad, level or ascending; valves 3–5, slightly exserted. [For more recent description see subspecies profiles-Editor]
Eucalyptus cinerea is one of the most popular of the temperate eucalypts in cultivation, especially in colder areas. It is commonly grown in southern Australia, New Zealand and many other countries. Eucalyptus cinerea has become naturalised in Canberra, Australian Capital Territory and no doubt in other places. It is weedy in Hawai'i.