Hypopyra vespertilio is a moth of the family Erebidae first described by Johan Christian Fabricius in 1787.

It is found in China, Korea, Honshu in Japan, India (Maharashtra, Jammu and Kashmir, West Bengal), Sri Lanka, Nepal, Thailand, Myanmar, Cambodia, Vietnam, Taiwan, Malaysia, the Philippines, Java, Sumatra and Sulawesi.

Male with an erectile tuft of long hair from femur-tibial joint of forelegs.

The darkest form is vespertilio which has the male dark brown; the costal and outer areas of forewing suffused with grey and olive; the stigma most developed; female much paler and greyer.

[4] The larvae feed on Albizia, Acacia, Wisteria and possibly Camellia species.