Carbon nanomaterials (CNMs)—fullerenes, carbon nanotubes (CNTs), and graphene-based structures—are transforming sustainable agriculture by their remarkable physicochemical, mechanical, and biological properties. CNMs improve seed germination, nutrient acquisition, and plant tolerance to abiotic stresses like drought, salinity, heavy metals, and temperature extremes. CNMs also serve as nanoscale carriers for site-specific delivery of agrochemicals for precision farming with smaller environmental footprints. Their incorporation into biosensors also enables real-time tracking of soil and crop health, enabling data-driven agriculture. Even with these developments, issues regarding phytotoxicity, environmental persistence, interactions with the microbiota of soil, and trophic transfer highlight the importance of careful deployment. The chapter covers different methods of synthesis and mechanisms of interaction with plants, environmental fate, and regulation. The objective of this chapter is to offer a critical overview of CNM types, synthesis techniques, agricultural uses, and environmental implications to provide an introductory point of view for academics, practitioners, and policymakers to inform the safe, innovative, and sustainable incorporation of carbon nanomaterials in contemporary agriculture.