The development of artificial diets is considered vital for feasible cephalopods’ culture. Octopus vulgaris need a diet with a high protein content but also lipids are important at a lower quantity, as polar lipids and LC-PUFA are essential for development during early stages. In the present study the suitability of marine lecithin as a dietary supplement for O. vulgaris juveniles’ formulated feeds was tested for 56 days, assessing the performance, changes in proximate composition, and lipid classes’ profile in the digestive gland and carcass. Sixteen octopus were fed one of two semi-moist feeds based on dry ingredients: either CALPRO (N = 4) as control or CALPRO-LM (N = 8); which differed from the first, due to the inclusion of 20 g/kg of marine lecithin as a phospholipid dietary supplement. Results showed that marine lecithin did not enhance feed intake, growth, protein or lipid incorporation, nutrients digestibility or feed efficiency. Moreover, at this level of inclusion, the composition of tissues (digestive gland and carcass) regarding macronutrients and lipid classes’ profile presented only a small amount of differences. In conclusion, the inclusion of marine lecithin did not promote beneficial effects on performance, making necessary further research related to the nutritional requirements of common octopus.