Mangrove plants, known for their rich biochemical diversity, have emerged as promising biofactories for the green synthesis of nanoparticles. This chapter explores the innovative potential of mangrove-derived nanoparticles, emphasizing their sustainable and eco-friendly applications across various sectors. These nanoparticles exhibit unique physicochemical properties due to the presence of natural bioactive compounds in mangrove extracts, facilitating the synthesis of metal and metal oxide nanoparticles such as silver, gold, zinc oxide, and iron oxide. This chapter highlights the multifaceted applications of these nanoparticles in biomedicine, including antimicrobial, anticancer, and antioxidant activities, which can revolutionize healthcare by providing eco-friendly alternatives to conventional treatments. Additionally, environmental applications such as wastewater treatment and pollutant degradation are discussed, showcasing their role in promoting sustainable environmental management. The use of mangrove-based nanoparticles in agriculture, particularly in the form of nanofertilizers and eco-friendly pest control agents, underscores their potential to enhance crop productivity while reducing chemical usage. Furthermore, this chapter delves into industrial applications, including catalysis and biosensing, where these nanoparticles offer green solutions to complex industrial challenges. Future perspectives suggest that with further research and technological advancements, mangrove-derived nanoparticles could play a significant role in achieving global sustainability goals.