Polysaccharides sourced from marine animal have gained an extensive interest as bioactive carriers used in targeted drug delivery systems, providing a variety of therapeutic options with the respect of ecological sustainability. In this sense, numerous compounds including chitosan, alginate, fucoidan, and carrageenan, derived from organisms such as crustaceans, mollusks, and algae-associated species, were found to exhibit remarkable properties including biocompatibility, enzymatic degradability, mucoadhesiveness, and reactive functional groups. These valuable characteristics facilitate their incorporation into a large range of delivery systems such as hydrogels, nanoparticles, microspheres, and nanofibrous scaffolds, ensuring an effective and proper control of drug release. The present chapter emphasizes the importance of marine polysaccharides and studies their potential properties for responsive delivery. It also discusses the recent innovations related to drug delivery systems including smart release systems and composite formulations that synergize marine polysaccharides with other materials. Furthermore, challenges and limitations are discussed as well as emerging strategies to improve delivery performance. Finally, the chapter highlights future directions and perspectives in marine-based drug delivery technologies, outlining their role in the era of next generation of precision therapeutics and regenerative remedies.