Abstract Two major challenges need to be overcome to bridge the efficiency gap between small-area rigid organic solar cells (OSCs) and large-area flexible devices: the first challenge lies in preparing high-quality flexible transparent electrodes with low resistance, high transparency, smooth surface, and superior mechanical properties. Second, the scalable fabrication of thickness-insensitive photoactive layers with low-cost materials is also an essential task. In this review, recent progress and challenges of flexible large-area OSCs are summarized and analyzed. Based on our analysis, strategies and opportunities are proposed to promote the development of stable and efficient flexible large-area OSCs.