Eucalyptus platypus is a mallee or a marlock that typically grows to a height of  and a width of   with a dense, rounded crown but does not form a lignotuber. The bark is smooth, brownish or copper-coloured. Young plants and coppice regrowth have egg-shaped to more or less round leaves  long and wide.
Eucalyptus species like mallees or marlocks generally reach heights of  and widths of   with a dense, rounded crown but do not develop lignotubers. The bark is smooth, exhibiting brownish or copper hues. Young plants and coppice regrowth display egg-shaped to round leaves, measuring  long and wide.