Metathrinca memnon is a moth in the family Xyloryctidae.

It is found in Sri Lanka.

The forewings are silvery white with the costal edge blackish towards the base and a slender slightly curved blackish streak from the dorsum beyond the middle, reaching about halfway across the wing.

There are several very fine linear dark-fuscous marks around the apex and termen.

This article on a moth of the family Xyloryctidae is a stub.