Eucalyptus ammophila is a mallee that grows to high, rarely a small, multistemmed tree, and forms a
lignotuber. The trunk has rough, fibrous, greyish brown bark and the upper parts of the trunk and the branches have smooth greyish and orange to bronze-coloured bark. Young plants and
coppice regrowth have square stems and broad lance-shaped to egg-shaped leaves that are long and wide with a short
petiole. Adult leaves are lance-shaped, long and wide with a petiole long. Both sides of the leaf are the same dull green, although bluish green at first. The flowers are arranged in groups of between seven and eleven in leaf
axils on a
peduncle long, each flower on a
pedicel about long. The mature flower buds are oval to spindle-shaped, yellow or cream-coloured, long and about wide. The
operculum is cone-shaped and about long. The fruit is a hemispherical
capsule long and wide with the four, sometimes five, strongly raised valves. ==Taxonomy and naming==