In recent years, the demand for effective electromagnetic interference (EMI) shields has surged owing to the proliferation of electronic devices and wireless communication systems. Due to their lightweight, flexible, and tunable electromagnetic properties, polymer–clay composites/hybrids have emerged as favorable materials in EMI shielding applications. This chapter provides an inclusive overview of the design, fabrication, and characterization of polymer–clay composites/hybrids tailored for EMI shielding purposes. The fundamental principles governing the electromagnetic behavior of polymer–clay/nanoclay systems are elucidated, encompassing aspects such as conductivity, dielectric properties, and electromagnetic wave absorption mechanisms. Various fabrication methods, including melt blending/compounding, solution casting, and in-situ polymerization, are discussed, as their influence on the resulting composite structure and performance. The synergistic effects arising from the combination of polymers and clays, as well as other functional fillers/additives, are highlighted, illustrating how precise control over material composition and structure can lead to optimized EMI shielding performance. Finally, current challenges and future directions in the polymer–clay composites/hybrids for EMI shielding are identified, offering insights into potential avenues for further research and development.