To address the challenges of persistent plastic pollution and food waste reduction, sustainable active packaging systems derived from renewable biopolymers represent alternative to non-renewable petroleum-based fossil plastics. In this context, an active, soil-biodegradable bio-packaging film was engineered via solvent casting from a synergistic binary blend of food grade carob seed flour (E410) and kappa-carrageenan (E407) plasticized with glycerol and functionalized with an aqueous extract from red pomegranate peel, a byproduct of pomegranate processing. The extract, recovered from this agricultural byproduct through ultrasound-assisted water extraction, exhibited rich phenolic, flavonoid, and anthocyanin contents together with strong radical scavenging capacity and broad-spectrum antibacterial activity against foodborne pathogens. When incorporated into the biopolymeric polysaccharide network, these bioactive constituents significantly enhanced tensile strength while maintaining high film flexibility and a hydrophobic surface character. The natural polyphenols were physically integrated into the matrix without disrupting the hydrocolloid framework. The functionalized films demonstrated antibacterial activity against Gram-positive and Gram-negative bacterial strains, good water vapor and gas barrier performance, and complete biodegradation in agricultural soil. Overall, this fully bio-based material demonstrates the technological potential of valorizing agro-industrial byproducts into high-performance active packaging capable of extending the shelf life of perishable food while aligning with circular bioeconomy frameworks.