2D nanomaterials have emerged as promising candidates for enhancing the efficiency and versatility of solar cell technologies. A viable contender for raising the effectiveness and adaptability of solar cell technology is 2D nanomaterials. These materials provide unique benefits for gathering, processing, and managing solar energy because of their excellent electrical, optical, and mechanical capabilities and atomic-scale thickness. The use of 2D nanomaterials in diverse solar cell topologies, including graphene, transition metal dichalcogenides (TMDs), and black phosphorus, has recently advanced. Furthermore, because 2D nanomaterials are mechanically flexible, they can be incorporated into lightweight, flexible solar cells, enabling applications in curved surfaces and wearable technology. Improved optical transparency and decreased resistive losses in solar cells have resulted from the inclusion of 2D nanomaterials as transparent conductive electrodes and interfacial layers. The synthesis methods designed for creating high-quality 2D nanomaterials and their incorporation into solar devices are covered in this chapter. These materials’ distinctive electronic structures allow for effective charge separation, transport, and collecting, which enhances photovoltaic performance. Additionally, incorporating 2D nanomaterials into tandem solar cells is made possible by the variable bandgaps and absorption spectra of these materials, allowing for improved spectrum utilization and total energy conversion efficiencies. Scalability, stability, interface engineering issues, and other difficulties with 2D nanomaterial-based solar cells are also included in this chapter. Techniques to reduce these difficulties such as hybrid nanostructures, surface passivation, and encapsulation are reviewed to establish long-term device reliability. In conclusion, 2D nanomaterials offer a game-changing way to improve the effectiveness and adaptability of solar cell technology. They provide prospects for creating innovative solar cell architectures with enhanced performance and expanded functionality thanks to their distinctive electrical, optical, and mechanical features. Addressing the current constraints would enable the widespread adoption of 2D nanomaterials in the upcoming solar energy harvesting systems as the field develops.