We evaluated the effects of the partial dietary replacement of fish meal with squid liver $Meal^{TM}$ on the growth and body composition of juvenile olive flounder Paralichthys olivaceus during the winter season. Twenty-five fish with an initial body weight of 23 g per tank were distributed among 12,250 L flow-through tanks. The experimental diets, which were designated SLM5, SLM1O, and SLM15 diets, were prepared in triplicate along with control diet by replacing 5, 10, and $15\%$ of mackerel fish meal with squid liver $Meal^{TM}$, respectively. The weight gain and specific growth rate of flounder that were fed the control and SLM5 diets did not differ from those of the fish fed the SLM10 diet, but they were significantly (P<0.05) higher than those of the fish fed the SLM15 diet. The feed efficiency ratios for the flounder that were fed the control, SLM5 and SLM10 diets were significantly (P<0.05) higher than for the fish that were fed the SLM15 diet. However, the protein efficiency ratio for the flounder was not significantly affected by the experimental diets. The crude protein, crude lipid and ash content, and blood chemistry of the flounder were not significantly affected by the experimental diets. Therefore, the replacement of up to $10\%$ of dietary fish meal with squid liver $Meal^{TM}$ can be made without a reduction in growth or a deterioration of the feed efficiency of juvenile olive flounder during the winter season.