This study investigated the impact of Arthrospira platensis (A. platensis) as a dietary supplement on growth, carcass criteria, liver and kidney function, lipid profile, and immunity of growing Japanese quails. In a 28-day experiment, 240 unsexed 7-day-old quail chicks were used. The quail chicks were divided into 4 treatment sets, each comprising 6 replicates and 10 quail chicks. Group (1) fed the basal diet with no supplements, group (2) fed the basal diet supplemented with 0.25 g A. platensis/kg diet, group (3) fed the basal diet supplemented with 0.50 g A. platensis/kg diet, and group (4) fed the basal diet supplemented with 1.00 g A. platensis/kg diet. The results of this study revealed that the birds that were fed 0.50 g. or 1.00 g A. platensis/kg diet had superior final body weights, body weight gains, feed conversion ratios, and carcass criteria compared to control, furthermore, had significant (P < 0.05) lower levels of liver enzymes and kidney function markers compared to control. Furthermore, birds fed 0.50 g or 1.00 g A. platensis/kg diet had significantly (P < 0.05) reduced cholesterol, triglycerides, and LDL cholesterol levels compared to control. Dietary supplementation of A. platensis at 0.50 and 1.00 g/kg diet significantly (P < 0.05) increased total antioxidant capacity, total immunoglobulin, and lysozyme activity levels. Using A. platensis at 0.5 or 1 g/kg diet levels during the Japanese quails' growth period can improve growth, carcass criteria, liver and kidney function, lipid profile, and immunity.