Currently, there is an increasing interest in microbial exopolysaccharides (EPSs) due to their diverse functionalities, diversity in chemical structure and source, and enormous potential for use in different medical applications. A novel marine Streptomyces sp. MAE (OR354383) was isolated and identified that generated a significant quantity of exopolysaccharide (EPS) at 7.6 g/L. Bioactive exopolysaccharide (EPSS10) was extracted and characterized from Streptomyces sp. MAE culture, and the molar ratio was determined via HPLC. Several methodologies were used to determine their antioxidant, antimicrobial, anti-inflammatory, anticancer, and antiviral activities. The anticancer efficacy of EPSS10 was evaluated using several cell lines (HepG2, CaCo2, MCF7, PC3, A549 and PANC1). Using Real time (RT)-PCR, we analyzed the expression levels of Bax, Bcl2, p53, Cytochrome c, and Caspase 9 in MCF7 cells. EPSS10 displays a grayish-white coloration, possesses an amorphous structure, and is devoid of odor. The composition of EPSS10 includes uronic acid (19.55%), sulfate (25.03%), and N-acetylglucosamine (10.63%). The in vivo toxicity results proved the safety of EPSS10 for biological parameters in rat models. EPSS10 demonstrates significant antibacterial efficacy. The maximum antioxidant was 89.21 ± 0.3% at 500 μg/ml; anti-inflammatory activity as cyclooxygenase (COX-1) inhibitory showed that the inhibition percentage was 81.9 ± 0.5%, and cyclooxygenase (COX-2) inhibitory provided 78.0 ± 1.2%. The fraction EPSS10 had a strong cytotoxic effect on different cancerous cells by increasing their concentrations. EPSS10 treatment increased Bax, Caspase 9, Cytochrome c, and p53 gene expression. The expression of the Bcl2 gene, however, was reduced. The antiviral efficacy of EPSS10 was determined to be 57.29 ± 1.78% at the maximum non-cytotoxic dose, whereas the concentration required to achieve a 50% reduction in the pathogenic effects of the Hepatitis A Virus (HAV) was 838.50 ± 34.62 μg/ml. The exopolysaccharide (EPSS10) of Streptomyces sp. MAE has important therapeutic potential due to its significant biological functions, safe use, structural features, and intrinsic qualities.