Hypselodoris decorata is a species of sea slug or dorid nudibranch, a marine gastropod mollusk in the family Chromodorididae.

It is reported from the Marshall Islands, Vanuatu, Indonesia, Papua New Guinea, the Philippines and Malaysia.

Hypselodoris decorata has a translucent cream to pink body with a broad brown band at the edge of the mantle and four thin opaque white lines on its dorsum.

The anterior end is usually light-purple in colour with white and dark purple spots and the gills have bright red-orange pigment on the apices and outer surfaces.

[3] Previously considered to be a colour variety of Hypselodoris maculosa the distinctive features of this species were elucidated by an integrated molecular and morphological study.