Eucalyptus sicilifolia is a tree that typically grows to a height of and forms a
lignotuber. It has rough, dark grey to black ironbark on the trunk and branches. Young plants and
coppice regrowth have stems that are square in cross-section and lance-shaped leaves that are long and wide. Adult leaves are the same shade of glossy green on both sides, narrow lance-shaped to curved, long and wide, with the base tapering to a
petiole long. The flower buds are arranged on the ends of the branchlets and in leaf
axils on a
peduncle long, the individual buds on
pedicels long. Mature buds are oval, long and wide with a conical to rounded
operculum. Flowering occurs from July to October and the flowers are white. The fruit is a woody cup-shaped to barrel-shaped
capsule long and wide with the valved near rim level. ==Taxonomy and naming==