Halgerda carlsoni is a species of sea slug, a dorid nudibranch, shell-less marine gastropod mollusks in the family Discodorididae.

The body is covered with tubercles of various sizes whose top is orange to red with a white rim at the base.

The background body colour is translucent white with dense punctuation of very small red-orange dots.

[3] Animals from East Africa differ in having lines or more continuous brown pigment on the rhinophores and gills instead of spots and are considered to be a distinct species by some authorities.

It has subsequently been reported from New Caledonia, Tonga, Sulawesi, the Philippines, Malaysia, Tanzania, Madagascar and South Africa.