Eucalyptus foliosa is a mallee that typically grows to a height of and forms a lignotuber. It has a dense crown of glossy green leaves that reaches to the ground. The bark is smooth and greyish with brownish patches and sometimes hangs in ribbons. The adult leaves are narrow lance-shaped or narrow oblong, the same colour on both sides, long and wide on a
petiole long. The flower buds are arranged in leaf
axils in groups of seven or nine on a
peduncle long, the individual buds on
pedicels long. Mature buds are shaped like an egg in an egg cup, about long and wide with a rounded
operculum. The flowers are white and the fruit is a woody, conical to shortened hemispherical
capsule long and wide with the valves near rim level. ==Taxonomy and naming==