Polyvinylidene fluoride (PVDF) has emerged as a multifunctional polymer in the field of flexible photovoltaics, offering critical benefits for both organic and perovskite solar cells. Its ferroelectric and piezoelectric properties enhance internal electric fields, promote exciton dissociation, and facilitate efficient charge transport. PVDF effectively passivates surface and grain boundary defects, suppresses ion migration, and improves film morphology, thereby boosting power conversion efficiency and device stability. Its hydrophobic nature protects devices from moisture and oxygen ingress, enhancing operational longevity. Compatible with low-temperature, solution-based processing techniques like spin coating and roll-to-roll fabrication, PVDF supports scalable and cost-effective device manufacturing. Additionally, its mechanical strength, flexibility, and environmental resilience make it an ideal substrate or interfacial layer for wearable and bendable solar applications. PVDF thus plays a pivotal role in advancing next-generation, high-efficiency, and durable flexible solar technologies.