It has thin, firm bark, elliptical, sharply-pointed leaves, greenish white or pink flowers and fruit that remain on the plant at maturity.

Leptospermum sphaerocarpum is a shrub that typically grows to a height of 2 m (6 ft 7 in) with thin, firm bark and young stems usually covered with soft hairs.

The flowers are greenish white or pink, mostly 15–20 mm (0.59–0.79 in) wide and arranged singly on short side shoots.

Flowering mainly occurs from October to November and the fruit is a capsule 7–10 mm (0.28–0.39 in) wide with woody valves and that remains on the plant at maturity.

[2][3] Leptospermum sphaerocarpum was first formally described in 1932 by Edwin Cheel in the Journal and Proceedings of the Royal Society of New South Wales, from specimens he collected near Rylstone.