Posidonia oceanica, an endemic seagrass species in the Mediterranean Sea, generates substantial amounts of stranded deposits on beaches. These deposits, though a nuisance, represent a valuable source of renewable material. Seagrassess are characterized by high lignocellulosic content, similar to land plants. In terms of sustainability, many researchers focused on the use of P. oceanica waste, which has many industrial, agricultural, and environmental applications. The current work discusses the methods of preparation, characterization, and different applications of lignocellulosic material extracted from P. oceanica stranded deposits, addressing their benefits as a readily available and renewable resource.