Marine sponge-associated Actinobacteria are important sources of structurally diverse secondary metabolites, including compounds with antibacterial and antifungal activities. Several extracts and characterized metabolites have shown activity against microorganisms relevant to food safety and spoilage, yet their potential use in food biopreservation remains poorly resolved. This structured narrative review examines the antimicrobial evidence available for marine sponge-associated Actinobacteria and evaluates how closely that evidence approaches practical food application. Current studies range from antimicrobial screening of isolates and crude extracts to metabolomic characterization and direct testing of purified compounds. Activity has been reported against food-relevant microorganisms including pathogenic Escherichia coli, Salmonella enterica, Bacillus cereus, Staphylococcus aureus, and selected postharvest fungi. However, most investigations remain concentrated at the discovery and in Vitro bioactivity stages, with limited validation under preservation-relevant food conditions. Important uncertainties remain regarding efficacy in complex food matrices, stability during processing and storage, food-use safety, sensory compatibility, scalable production, and regulatory suitability. Future development should therefore focus on a smaller number of well-characterized candidates and progress them through quantitative antimicrobial validation, food-relevant target testing, matrix-specific challenge studies, safety and sensory assessment, and food-grade production. Marine sponge-associated actinobacterial metabolites consequently represent credible antimicrobial candidates for further food-oriented investigation, but their value for biopreservation will depend on translational validation rather than antimicrobial activity alone.