Increasing pressure from global climate change and intensive agricultural practices stresses plants, potentially affecting productivity and food security. In this context, nanotechnology offers a novel approach, with carbon nanotubes (CNTs) emerging as a highly promising method for mitigating plant stress. This chapter explores how CNTs can be used to enhance plant resistance to both abiotic and biotic stresses. Firstly, CNTs improve photosynthetic efficiency by maintaining the activity of artificial light-harvesting antennas that expand spectral absorption and facilitate more efficient electron transfer. Consequently, both photosynthetic capacity and biomass production are bolstered even under stress conditions. Additionally, CNTs are effective in mitigating oxidative stress, thanks to their nanozyme property, which allows them to scavenge harmful reactive oxygen species. This function helps strengthen the plant’s natural defenses against oxidative damage, promoting cell survival. Their physicochemical features, such as high surface area and permeability, enable efficient nutrient and water uptake. Moreover, CNTs can serve as carriers for various agrochemicals essential for root development, increasing nutrient availability in the rhizosphere. By combining these key functions, photosynthetic stimulation, oxidative stress alleviation, and improved nutrient acquisition, this chapter highlights the potential of CNTs as a green nano-priming agent capable of supporting plant growth and maintaining yield under challenging environmental conditions.