Sustainable agricultural practices are inevitable for long-term benefits under changing climate scenarios. The utilization of nanomaterials as nanofertilizers is important to enhance nutrient use efficiency, reduce environmental impacts, and support the resilience of agricultural systems in the face of climate change. Nanofertilizers possess unique properties, such as enhanced solubility, controlled release of nutrients, and increased surface area that enable precise nutrient delivery to plants with minimum loss. This chapter focuses on the potential use of nanomaterials in synthesizing nanofertilizers (physically, chemically, and biologically) and the effects of nanoparticles/nanofertilizers on plant growth and development with emphasis on how nanofertilizers can optimize nutrient uptake, reduce nutrient loss, and minimize the excessive use of conventional fertilizers, in order to address the key challenges of modern day agriculture. The role of nanofertilizers in mitigating abiotic stresses is also emphasized by showing their potential to improve crop resilience under sub-optimal conditions. Either via soil or foliar application, the nanofertilizers were found beneficial regarding crop growth and yield improvement than conventional fertilizers. Additionally, the short- and long-term benefits of nanofertilizers include improvement in nutrient use efficiency, plant and soil health, less environmental pollution, an alternative to conventional fertilizers, and a step toward climate-smart agriculture. Overall, nanomaterials as nanofertilizers present a promising strategy for advancing climate-smart agriculture, offering a pathway to more sustainable, resilient, and efficient agricultural systems globally.