Nembrotha lineolata is a species of nudibranch, a sea slug, a marine gastropod mollusk in the family Polyceridae.

The oral tentacles are thick and long and the large conical rhinophores bear about thirty lamellae and can be retracted.

The body colour is creamy-white with narrow longitudinal lines, some broken, in varying shades of brown.

[2][3] This is a widespread Indo-Pacific species occurring from the East African coast to Australia, Fiji and the Solomon Islands.

In one attack on Nembrotha lineolata, the sea slug flinched whenever it was touched by a tentacle but oozed a great deal of mucus and managed to struggle out of reach.