Goniobranchus splendidus is a species of colourful sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae.

[2][3] The specific epithet splendida means splendid in reference to the colouring, because this nudibranch has large red spots on a white background, a yellow line at the mantle edge, and magenta rhinophores.

[1] It is one of a group of similar red-spotted chromodorids from south-eastern Australia which form a mimicry ring.

[4][5] Goniobranchus splendidus is a chromodorid nudibranch which has an opaque white mantle with large, scattered red spots.

In the northern part of its range these spots coalesce and may form a single large red patch in the middle of the back.