Fjordia lineata is a species of sea slug, an aeolid nudibranch, a marine heterobranch mollusc in the family Flabellinidae.

[2] Fjordia lineata are commonly 20-30mm (2-3 cm) in length and are seen in a variety of colours, translucent white with either red, red-brown, yellow, or orange colouring of the digestive gland within the cerata.

[3] This species feeds on hydroids such as Tubularia indivisa.

[4] Fjordia lineata can be found throughout the British Isles, and can also be found south as far as the Mediterranean Sea and north to Norway.

[3]