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

[2] This species was described from Naples, Italy.

It has also been reported from Numana, Ancona, Italy and the Mediterranean Sea coast of Spain.

[3][4] Knoutsodonta neapolitana feeds on the bryozoan Schizobrachiella sanguinea.

[3]