Endophytic fungi are known for diverse bioactive compounds and pharmaceutical potential. This study assessed antioxidant activity of fungi isolated from green and brown algae. DPPH and reducing power assays measured antioxidant properties of strains (Fug 03–07). Fug 05 showed the strongest inhibitory effect across all concentrations; ascorbic acid exhibited similar low OD values confirming high efficacy. Fug 09 had highest inhibition at lower concentrations, while Fug 07 dominated at higher concentrations. Results indicate concentration-dependent antioxidant potency, suggesting potential applications. Further studies are needed to explore mechanisms and commercial use.