Posidonia oceanica is a native Mediterranean seagrass forming big grasslands throughout the coastline and playing a primary role in the Mediterranean ecosystems, oxygen regeneration, water filtration, and increasing the total organic carbon in seabed. Nevertheless, large volumes of Posidonia wrack (leaves and rhizomes) deposit onto beaches Posidonia, during the winter, poses a range of challenges for local authorities, such as odor and visual appearance which reduce beach use and imply substantial economic costs for its removal. P. oceanica wrack are often removed as part of beach cleaning activities in many localities and are disposed into landfills. Such conventional management strategy is responsible for the loss of valuable organic carbon waste that could be converted into biofuel and soil organic amendment. Through the last decades, Posidonia was used as feedstock for both biochemical and thermochemical conversion processes to produce biofuel and materials. Furthermore, attempts were also made to produce a compost-based Posidonia with good agronomic quality. Based on the findings of previous studies, P. oceanica could be considered as a potential biomass resource to develop biofuel and organic agriculture sectors in the Mediterranean region by adopting a circular economy approach. Nevertheless, modification methods are required to enhance the biological conversion of Posidonia into biogas and bioethanol. Further investigations are required to determine the salinity risk associated with the use of soil organic amendment produced from P. oceanica.