Thumatha fuscescens is a moth of the family Erebidae first described by Francis Walker in 1866. It is found in Australia, South-East Asia, India, Sri Lanka, the Comoros, Réunion, Madagascar, and Gabon.
The species wingspan is . The male has a pale reddish-brownish body. Forewings possess traces of antemedial and postmedial waved lines. There is a black spot at end of the cell and a spot on the costa before apex. Sub-marginal and marginal specks series present.
The larva is known to feed on lichens and mosses.