Marine polysaccharides, due to their non-toxic, biocompatible and biodegradable nature, are considered as safe carrier materials for pulmonary drug delivery application. Marine polysaccharides, including fucoidan, alginate, agar, carrageenan, hyaluronic acid, chitosan and chondroitin sulphate, promote pulmonary drug delivery by minimizing protein corona formation; enhancing mucus diffusion, muco-adhesion and lung retention time; facilitating paracellular and transcellular drug transport via protein kinase pathway; increasing cell internalization; and reducing transepithelial electrical resistance. Marine polysaccharides, with molecular weights ranging from 10 to 3400 kDa, can deliver therapeutic agents into different regions of the lungs by modulating particle size for inhalation and targeting the macrophage or lung cell surface/P-selectin/CD44/hyaluronan receptors. Marine polysaccharides possess diverse functional groups, particularly sulphate, carboxyl, hydroxyl, acetamido and amino groups, which facilitate their formation into nano-/micro-complexes, enable hydrogen bond and hydrophilic character development and allow chemical modification into various functional derivatives to meet drug release and targeting functions. Thus far, the majority of research findings are obtained in vitro and in vivo. Its clinical translation requires human trials.