This study explores the effects of γ-irradiation on various phytochemical constituents of Scenedesmus obliquus, including proanthocyanidins, saponins, β-carotene, proteins, vitamins (B₁, B₂, B₃, B₆, A, and K), amino acids, and fatty acids. Cultures of S. obliquus were subjected to a γ-irradiation dose of 300 Gy and were analyzed after 20 days of growth. The results indicated significant changes in the phytochemical profile of the irradiated algae. Proanthocyanidins and saponins levels increased, suggesting an enhanced secondary metabolite production. In addition, β-carotene content increased, indicating an improved antioxidant capacity. Protein levels were significantly higher, reflecting an increased biosynthetic activity. Vitamin analysis showed substantial increases in the contents of B₁, B₂, B₃, B₆, A, and K, highlighting the potential nutritional benefits of γ-irradiated S. obliquus. Amino acid profiling revealed higher concentrations of essential amino acids.  Fatty acid analysis identified twelve fatty acids, predominantly composed of fatty acid methyl esters, which include both saturated and unsaturated fatty acids with carbon chain lengths ranging from C12 to C24. These findings suggest that γ-irradiation at 300Gy can effectively enhance the phytochemical constituents of S. obliquus, potentially improving its applications in nutrition and biotechnology.