Regarding the challenges posed by climate change, rising global food demand, and declining arable land, investigating innovative agricultural practices is important. Biogenic metallic nanoparticles (BMNPs) are among the most promising technologies in sustainable agriculture due to their enormous potential as effective fungicides and fertilizers. The remarkable characteristics of BMNPs, including their large surface area, responsiveness, and controlled nutrient release, intrigue them. These nanoparticles are also more easily absorbed by plants, distributed throughout their tissues, and affect their metabolism than chemicals. These features make them ideal for enhancing plant growth and safeguarding crops against infections. For instance, their regulated delivery of nutrients can lower nutrient loss and the requirement for traditional fertilizers. The benefits of BMNPs for the environment are also noteworthy. It can contribute to a more sustainable approach to agriculture by lowering toxicity to non-target organisms and dependence on chemical inputs. Synthesis, characterization, and application of BMNPs are covered in this chapter, with a focus on improving agricultural yield and disease control. This chapter attempts to give a better understanding of how BMNPs can support sustainable farming practices by analyzing current studies and field experiences.