Nanotechnology has emerged as a recent, efficient and transformative tool in the domain of plant sciences, offering novel solutions to long-lasting challenges in agriculture, biotechnology, and environmental sustainability. Nanoparticles (NPs) are structures with small size between 1 and 100 nm that possess unique physico-chemical properties due to their high surface area to volume ratio. NPs are classified into diverse range of categories including organic, inorganic and carbon-based. The synthesis of NPs ranges from conventional physical and chemical methods to eco-friendly biological (green) synthesis using plant extracts, microbes, algae and fungi emphasizing their comparative advantages and limitations. This chapter further elaborates the multifaceted applications of NPs in plant sciences, such as enhancing nutrient delivery through nanofertilizers, improving crop protection via nanopesticides, facilitating genetic transformation, and strengthening plants’ resistance to biotic and abiotic stresses. Overall, this chapter underscores the growing importance of nanotechnology as a sustainable and efficient platform for advancing plant sciences in the era of climate change and food security challenges.