Eudonia oreas is a moth in the Crambidae family. It was described by Meyrick in 1885. It is found in New Zealand. The wingspan is about 22 mm. The forewings are white, mixed with pale grey and thinly irrorated with dark fuscous. There are some obscure dark fuscous spots near the base. The first line is white, margined with dark fuscous posteriorly. The second line is white, margined with dark fuscous. The hindwings are grey-whitish with a slightly darker apex. Adults have been recorded on wing in December.