Today, ionic liquids stand out as a new class of chemical compounds that enable the development of versatile and high-performance materials. Due to their distinctive properties such as low vapor pressure, high thermal stability, non-flammability, strong ionic conductivity, and a wide electrochemical window interest in ionic liquids has been steadily increasing. The properties of ionic liquids can be tuned across a broad range by integrating specific functional groups into the cation, the anion, or both. Combining ionic liquids with polymers allows for the synergistic merging of the unique characteristics of both components, enabling the design of smart and functional composite materials. The structural or chemical modifiability of both the ionic liquid and the polymer matrix makes it possible to obtain a wide variety of functional composites and develop materials tailored to the specific requirements of different applications. In this context, smart ionic liquid/polymer-based materials are being designed and developed for a broad spectrum of applications, particularly sensitive and responsive sensors, actuators, environmental monitoring systems, batteries, fuel cells, and biomedical technologies.