Quantum dots (QDs), with carbon dots (CDs) emerging as a prominent subclass, have become transformative nanomaterials for enhancing photosynthesis and agricultural productivity. Their tunable photophysical properties enable the modification of the light spectrum by converting ultraviolet light into photosynthetically active radiation, which optimizes chloroplast light absorption and energy utilization. Early research using traditional QDs such as CdTe and CdSe demonstrated improved electron transport, enhanced chlorophyll fluorescence, and increased energy conversion in photosystems, though heavy metal toxicity remains a concern. In contrast, carbon dots offer a safer and more biocompatible alternative, exhibiting excellent light absorption, customizable luminescence, and versatile surface chemistry. Studies have shown that CDs boost key photosynthetic processes by increasing RuBisCO activity, stimulating chlorophyll synthesis, and mitigating abiotic stresses through effective reactive oxygen species scavenging and enhanced nutrient uptake. Integration of these QDs into agricultural practices, ranging from greenhouse covering materials and LED lighting systems to foliar applications and nanocapsules, has led to significant improvements in crop yield and plant resilience. Future research should focus on optimizing QD formulations and delivery methods to maximize photosynthetic enhancement while ensuring environmental sustainability, thereby paving the way for revolutionary advances in modern agriculture and artificial photosynthesis.