In the last decade, ionic liquids (ILs) have been established as notable solvents with applications in various scientific and technol. fields.Due to their adjustable nature and unique attributes, ILs play a fundamental role in organic synthesis, biotechnol., energy storage systems, and pharmaceutical chem.This review highlights the potential of ILs as phase change materials (PCMs) for enhancing thermal properties, ensuring thermal stability, and addressing environmental concerns.It provides a comprehensive overview of IL-PCM composites, focusing on their synergistic effects, benefits, and challenges.The review concludes that ILs significantly improve the efficiency and application range of PCMs in thermal energy storage and solar energy systems.Furthermore, IL-PCM composites demonstrate enhanced thermal conductivity and environmental benefits, paving the way for innovative solutions in energy management.