Aldisa banyulensis is a species of sea slug, a dorid nudibranch, a marine gastropod mollusk in the family Cadlinidae.

[3] Aldisa banyulensis is a small sea slug that is normally 8–12 mm in length.

It is red or orange-red in colour with two oval markings on the midline of the back which resemble the inhalent pore-sieves of its sponge food.

There are pale streaks running from the sides of the back to the edge of the mantle and between the rhinophores.

[4] This species is reported to feed on the sponge Hemimycale columella (Hymedesmiidae).