Eucalyptus froggattii is a mallee that typically grows to a height of or a tree to and forms a
lignotuber. It has rough, crumbly blackish bark on the trunk, smooth grey to brown bark that is shed in ribbons above. Young plants and
coppice regrowth have glossy green,
petiolate, lance-shaped to curved leaves that are long and wide. Adult leaves are the same glossy, light green on both sides, lance-shaped to curved, long and wide on a petiole long. The flower buds are arranged on the ends of branches in groups of seven, nine or eleven on a branching
peduncle long, the individual buds on
pedicels long. Mature buds are club-shaped to diamond-shaped in side view, more or less square in cross section with a rib along each corner, long and wide with a pyramidal to conical
operculum. The flowers are white to cream-coloured, cup-shaped to pear shaped in side view, square in cross section, long and wide with the valves enclosed below rim level. ==Taxonomy and naming==