Euthalia mahadeva is a butterfly of the family Nymphalidae (Limenitidinae). It is found in the Indomalayan realm.
Males have a dark dusky brown upperside smeared with purple on the exterior margin of the fore-wing and hind-wing with a broad band to the exterior margin, whitish anteriorly, bluish posteriorly, with a central longitudinal row of small, dusky spots. The underside is light brown, with greyish exterior margins, discoidal marks and a submarginal row of indistinct blackish spots.