Dendronotus iris, also known as the rainbow nudibranch, is a species of sea slug, a dendronotid nudibranch, a shell-less marine gastropod mollusc in the family Dendronotidae.

[1] It can be found along the west coast of North America from Unalaska Island, Alaska to Cabo San Lucas, Baja California.

Distinctive features include the stalk of the rhinophore sheath having a vertical row of three to six small branched processes on its posterior side, and the foot being edged in white, although this may be partially absent in some specimens.

The branching gills may be tipped with white, orange, yellow, or purple.

[6] This species feeds on the burrowing anemone Pachycerianthus fimbriatus.