The olive flounder (Paralichthys olivaceus) is an important economic aquaculture species in Korea, Japan, and China. The Eastern Marine Biology Research Center of Fisheries Research Institute has imported flounder fry, successfully established breeding technology since 2014, and promoted this the private sector for aquaculture. However, during different breeding periods, the breeding density, illumination, and other conditions will affect the growth of P. olivaceus. Therefore, this study investigated the effects of the lighting, substrate conditions, and breeding density during different breeding periods on the growth of P. olivaceus to establish the most suitable breeding conditions and provide reference applications for the aquaculture industry. The breeding density experiment during different breeding periods was conducted for 6 weeks. The results showed that the initial body weight of the flounder was 7.86 ± 1.29 g when the breeding density was 100/m2, and the weight gain rate of 599 ± 7% was the best. When the initial body weight was 106.87 ± 7.32 g and the breeding density was 60/m2, the weight gain rate was 100 ± 8%. Additionally, when the initial body weight was 323.33 ± 16.47 g and the breeding density was 20/m2, the weight gain rate of 58 ± 9% was the best. Moreover, when the initial body weight was 532.64 ± 8.93 g and the breeding density was 15/m2, the weight gain rate of 24 ± 6% was the best. The results of the illumination experiment showed that the best weight gain rate was 309 ± 2% under an illumination of 800 to 1000 lux. The results of the aquaculture substrate experiment showed that the weight gain rate of the group without the fine coral sand was 31 ± 1% better than the group with fine coral sand.