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

[2] This marine species occurs in the Western Pacific.

It has been reported from American Samoa, the Marshall Islands and the Philippines.

[3][4] Goniobranchus rubrocornutus is a chromodorid nudibranch with a semi-translucent white mantle and coloured margin.

The body reaches a length of 15 mm.