Leionema ellipticum is a small shrub to 2 m (6 ft 7 in) high with smooth, glossy, more or less terete branchlets.

The sepals are shortly attached to the base of the flower, fleshy, triangular shaped, about 0.8 mm (0.031 in) long and bracteoles falling off early.

The white petals are about 4.5 mm (0.18 in) long, narrow oval shape, smooth and prominently keeled.

[3][4] The specific epithet (ellipticum) is derived from the Latin elipticus referring to the shape of the leaves.

[3] This species has a restricted distribution found growing at a windy, mountainous location in north-east Queensland.