Speiredonia mutabilis is a species of moth of the family Erebidae first described by Johan Christian Fabricius in 1794.

It is found in India, Sri Lanka, Vietnam, Taiwan, the Philippines, from Sundaland eastwards to Australia, the Solomon Islands, New Caledonia, Vanuatu, Fiji and Tonga.

Adult blackish brown with purplish tinged.

Forewings with waved sub-basal, antemedial, and medial black lines.

An indistinct sinuous sub-marginal double line also present.