Green synthesized nanoparticles from marine plants have gained significant demand as natural nanomedicines for drug delivery research, biosensing application, agro-industrial applications, biomedical industry, and textile industries. This book aimed to provide a timely comprehensive knowledge on different aspects of marine flora (seaweeds, seagrasses, mangroves, and other coastal plants)-derived nanoparticles (MFNPs). This comprehensive book has treatise more than twenty different applications of green synthesized metal (Ag, Au, Cd, Cu, Fe, Pd, Se) and metal oxide (CdO, CuO, Cu2O, Cu/Cu2O, Fe3O4, TiO2, ZnO, Ag-ZnO, CdO-ZnO) nanoparticles derived from MFNPs. This book offers a detailed analysis of MFNPs, encompassing their synthesis, characterization, physiological properties, and regulatory factors. This book not only presents a comprehensive overview of MFNPs but also identifies key research gaps, outlining future directions for investigation. As such, it serves as a valuable resource for researchers and professionals in the field, offering actionable insights to propel advancements in MFNP research and applications. By providing a thorough understanding of MFNPs, this book aims to facilitate breakthroughs in the development and utilization of these innovative materials.