Hypselodoris apolegma (or "Bubblegum Worm" as it is commonly known) is a species of colourful sea slug or dorid nudibranch, a marine gastropod mollusk in the family Chromodorididae.
Recent phylogenetic data confirm the validity of the species and suggest a sister species relationship between Hypselodoris apolegma and Hypselodoris bullockii. A later study revealed a large clade of animals with similar colouration with Hypselodoris brycei as sister species to H. apolegma.
This nudibranch is found in the tropical Western Pacific Ocean.