Euphaea masoni is a species of damselfly in the family Euphaeidae, the gossamerwings.
The male is almost entirely black, including its wings. The female has lighter colored wings.
Euphaea masoni is found mostly in Southeast Asia, including southern China, India, Laos, Myanmar, Thailand, Vietnam.
It is found near streams. Phoretic associations between larvae of Nanocladius asiaticus (Diptera, Chironomidae) and Euphaea masoni have been reported.