Tenellia pinnifera is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusc in the family Fionidae.

This species was described from Sagami Bay, Japan.

It was subsequently reported from Kii Peninsula, Osaka Bay, Toyama Bay and Tsuruga Bay.

[2] This Tenellia is a white animal with a single, broken, band of orange-yellow below the tip of the cerata.

[3]