Nanoscience has become a fundamental component of modern technology due to its wide range of applications and together with nanotechnology represents one of the most active areas of research within the agricultural area. Nanotechnology in agriculture promises to greatly optimize numerous characteristics of crops, thus improving their commercial value and contributing to substantial economic gains. To meet the growing demand for nanoparticles and nanomaterials, researchers have employed various strategies to synthesize them. The most commonly used methods in synthesis are usually physical and chemical techniques; however, their large-scale production can be limited due to factors such as high costs associated with energy consumption, use of hazardous chemicals, harmful solvents, and the production of toxic by-products that contribute to environmental pollution and various biohazards. Green synthesis is an up-to-date technology that leads to sustainable solutions because it uses biological agents such as plants and/or highly compatible microorganisms for the synthesis of nanoparticles. This technique has advantages over physical and chemical methods as it is more environmentally friendly due to the fact that it does not require or generate hazardous chemicals. This review discusses the various approaches to nanoparticle synthesis with a focus on ecological synthesis and the mechanism of action and impact of nanoparticles on plant systems.