Nanotechnology has great potential for developing nano-enabled equipment and products in a variety of industries, including personal care, medical, food, and agriculture. Despite the increasing use of metal nanoparticles in various domains, concerns concerning biological and environmental safety during manufacture remain. Traditional commercial methods for generating nanoparticles often entail chemical procedures and high-energy physical approaches that are both environmentally damaging and expensive. As an alternative, green synthesis employing plants has arisen, which reduces the requirement for toxic chemicals and severe reaction conditions in nanoparticle synthesis. The utilization of mangrove plants for nanoparticle synthesis has recently gained popularity due to their abundance of unique phytochemicals that aid in nanoparticle synthesis. Microorganisms in mangroves and enzymatic activities in plants can be utilized for a range of biotechnological and environmental uses. Bioactive compounds from mangrove resources show potential for creating bionanomaterials that can be utilized in environmental and biomedical fields. Bionanomaterials created from mangroves are incredibly effective in medical uses and cleaning up the environment. Bionanomaterials are produced by utilizing mangrove and various biomolecules obtained from mangrove plants as substances for the creation of nanoparticles. Bionanomaterials made from biomolecules offer benefits for the sustainable use of mangroves because of their large surface area, biocompatibility, and minimal toxicity. Here focuses on the potential of mangroves as a natural resource for producing bionanomaterials in various applications, promoting an eco-friendly approach. This chapter investigates various types of mangrove species and their elements utilized in creating nanoparticles, as well as the applications of the nanoparticles in therapy, agriculture, and industry. It also investigates the obstacles hindering the extensive utilization of plant-based nanoparticle synthesis.