The global energy sector is undergoing a transformative shift towards clean, sustainable, and reliable energy solutions. The integration of renewable energy sources (RES) such as wind, solar, and hydropower faces significant challenges due to their intermittent and variable nature, affecting grid stability and reliability. Hybrid energy storage systems (HESS) that combine multiple energy storage devices (ESDs) offer a promising solution by leveraging the complementary strengths of different technologies. This review examines recent advancements in grid-connected HESS, focusing on their components, design considerations, control strategies, and applications. It highlights the technological progress in various ESDs and the critical role of power conversion, control, energy management, and cooling systems in optimizing HESS performance. Case studies of successful HESS implementations worldwide illustrate practical applications and identify benefits and challenges. By addressing these challenges, HESS can enhance the efficiency and reliability of RES, supporting the transition to a sustainable and resilient energy infrastructure. The paper concludes by identifying future research directions, emphasizing the development of intelligent control systems, sustainable materials, and efficient recycling processes to ensure the widespread adoption and long-term viability of HESS.The global energy sector is undergoing a transformative shift towards clean, sustainable, and reliable energy solutions. The integration of renewable energy sources (RES) such as wind, solar, and hydropower faces significant challenges due to their intermittent and variable nature, affecting grid stability and reliability. Hybrid energy storage systems (HESS) that combine multiple energy storage devices (ESDs) offer a promising solution by leveraging the complementary strengths of different technologies. This review examines recent advancements in grid-connected HESS, focusing on their components, design considerations, control strategies, and applications. It highlights the technological progress in various ESDs and the critical role of power conversion, control, energy management, and cooling systems in optimizing HESS performance. Case studies of successful HESS implementations worldwide illustrate practical applications and identify benefits and challenges. By addressing these challenges, HESS can enhance the efficiency and reliability of RES, supporting the transition to a sustainable and resilient energy infrastructure. The paper concludes by identifying future research directions, emphasizing the development of intelligent control systems, sustainable materials, and efficient recycling processes to ensure the widespread adoption and long-term viability of HESS.