Eucalyptus caesia, commonly known as caesia or gungurru, is a species of mallee that is endemic to the south-west of Western Australia. It has smooth reddish brown bark at first, later shedding in curling flakes, lance-shaped, sometimes curved adult leaves, club-shaped flower buds covered with a waxy, bluish white bloom, pink stamens with yellow anthers and urn-shaped fruit.
Eucalyptus caesia is a mallee that typically grows to a height of 2 to 14 metres (6.6 to 45.9 ft) and forms a lignotuber. The bark is smooth reddish brown at first and is shed in curling longitudinal flakes known as "minnirichi". Young branches are shiny red, covered with a waxy, bluish white bloom. Young plants and coppice regrowth have thick, glossy green, heart-shaped leaves 25–80 mm (0.98–3.1 in) long and 25–60 mm (1–2 in) wide that have a petiole. Adult leaves are lance-shaped to curved, mostly 80–110 mm (3.1–4.3 in) long and 15–25 mm (0.6–1 in) wide on a petiole 10–35 mm (0.39–1.4 in) long. The flower buds are arranged in leaf axils in groups of three on an unbranched peduncle 15–35 mm (0.59–1.4 in) long, the individual flowers on pedicels 15–22 mm (0.59–0.87 in) long. Mature flower buds are oval or pear-shaped, covered with a whitish waxy bloom, 17–30 mm (0.67–1.2 in) long and 10–13 mm (0.39–0.51 in) wide with a conical operculum. Flowering mainly occurs between May and September and the flowers have pink stamens with yellow anthers on the tip. The fruit is a woody bell-shaped or urn-shaped capsule 15–25 mm (0.59–0.98 in) long and 18–23 mm (0.71–0.91 in) wide on a peduncle 13–33 mm (0.51–1.3 in) long.