It has rough, flaky bark, broadly elliptical to egg-shaped leaves with the narrower end towards the base, and a sharply-pointed tip, white flowers and fruit that remains on the plant at maturity.

The floral cup is covered with soft hairs, about 4 mm (0.16 in) long tapering to a very short pedicel.

Flowering mostly occurs from December to March and the fruit is a capsule about 10 mm (0.39 in) wide that remains on the plant at maturity.

[2][3][4] Leptospermum thompsonii was first formally described in 1989 by Joy Thompson in the journal Telopea from specimens collected by John Boorman in 1915.

The main threats to the species are altered fire regimes, forestry activities, rubbish dumping and oil spills.