Single‐junction organic solar cells (OSCs) have made significant progress in recent years. Innovations in material design and device optimization have improved the power conversion efficiencies to over 19 %. In this Minireview, based on recent advances, we discuss molecular design strategies to tune the absorption spectrum, energy level, and intermolecular aggregation as well as highlight the role of molecular electrostatic potential in decreasing energy loss. Then, we introduce the latest progress in four types of OSCs composed of different donor:acceptor combinations: polymer donor:small‐molecule acceptor, all‐polymer, all‐small‐molecule, and small‐molecule donor:polymer acceptor. Finally, the challenges of OSCs in practical applications, including material cost, stability, and multi‐function integration, are discussed. Organic solar cells (OSCs) are a promising next‐generation photovoltaic technology with many unique advantages. This Minireview highlights the recent advances in material design and cutting‐edge devices. Particular attention is paid to a few research directions toward practical applications of OSCs.