Onchidoris proxima is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Onchidorididae.

Previously in the genus Adalaria this species was moved to Onchidoris as a result of a molecular phylogeny study.

The mantle is covered with club-shaped tubercles with pointed ends which are stiffened with calcareous spicules (spine-like structures).

The blunt-ended rhinophores (sensory tentacles on the head) are often darker in colour than the rest of the animal, and each bears up to nineteen thin plates.

[4][6] It also feeds on other species of bryozoa such as Membranipora membranacea, Alcyonidium polyoum and Flustrellidra hispida if Electra is not available.