Mecyna flavalis is a species of moth in the family Crambidae.

It is known from most of Europe (except Ireland, Norway, Portugal, Slovenia and Ukraine)[1] to Japan.

[2] The species was first described by Michael Denis and Ignaz Schiffermüller in 1775.

Adults are on wing from July to August.

[3] The larvae feed on Galium mollugo, Artemisia campestris, Ballota, Reseda and Urtica urens.