Clear aligners have emerged as a cornerstone of modern orthodontics, blending aesthetics with functionality. Recent breakthroughs in material science have propelled these devices beyond their traditional limitations, enabling precise tooth movements and improved patient compliance. This review examines the latest advancements in clear aligner materials since 2020, focusing on novel polymers, nano composites, and smart materials. Their mechanical properties, clinical performance, and environmental impact are critically analyzed, alongside future trends in sustainable and AI-driven orthodontic solutions.