Ariadne pagenstecheri, the Pagenstecher's castor or scalloped castor, is a butterfly in the family Nymphalidae.

It is found in Nigeria, Cameroon, the Central African Republic, southern Sudan, Uganda, Rwanda, Burundi, western Kenya, north-western Tanzania and the eastern and central parts of the Democratic Republic of the Congo.

[2] The habitat consists of the margins of sub-montane and montane forests.

The larvae feed on Tragia brevipes.

This article related to members of the butterfly subfamily Biblidinae is a stub.