Delias harpalyce, the imperial white, is a butterfly in the family Pieridae.

The upper surfaces of the forewings and hindwings are a whitish with black margins and a row of small whitish spots on the apex of the forewings.

In the females the black outer edges of the wings are wider than in males.

[1][2] The larvae are about 4 cm in length, with a black body covered by white hairs.

These gregarious caterpillars spin a silken web on their host plants, including Amyema, Muellerina and Dendrophthoe species.