Nanotechnology has emerged as a rapidly expanding branch of science having significant roles in diverse number of fields. Different types of nanoparticles being investigated for various purposes due to their unique chemical and physical properties have attracted the attention of researchers from all scientific disciplines. Carbon nanomaterials (CNMs), such as fullerenes, fullerols, carbon nanotubes, graphene, carbon dots, and nanoporous-activated carbon, are being particularly exploited. Specifically being used in the agricultural sector, they have been found to enhance the food production and develop sustainable agricultural practices. They have shown a remarkable ability to boost nutritional content, activate gene expression, and promote the development of bioactive compounds and metabolites. However, with varying environmental conditions and concentrations, they have been found to impart various toxic effects as well including increasing phytotoxicity, reactive oxygen species production, and cell death. The differences in the responses of plant toward CNMs are found to be dependent on the type of plant species and the stage of its lifecycle, along with the morphology and surface properties of the nanoparticles being used. This chapter summarizes the use of different types of CNMs on different plant species in varying conditions to observe the complex interactions between these nanomaterials and plants having significant roles in plant cell toxicity, nutrient dynamics, and the accumulation of bioactive compounds.