Digital Smile Design [DSD] has transformed esthetic dentistry by integrating digital technology, facial analysis, and restorative planning to improve treatment predictability and patient satisfaction. Conventional smile design techniques often lacked precision, reproducibility, and effective communication. The development of DSD has addressed these limitations through the use of digital photography, intraoral scanning, CAD-CAM systems, virtual simulations, and artificial intelligence. This review discusses the evolution, principles, technological foundations, clinical workflow, applications, advantages, limitations, and future perspectives of DSD. The technology has enhanced interdisciplinary treatment planning in esthetic rehabilitation, orthodontics, implant dentistry, and full-mouth reconstruction while improving patient communication and diagnostic accuracy. Emerging technologies such as artificial intelligence, augmented reality, and cloud-based workflows are expected to further expand its role in personalized dentistry. Despite its advantages, challenges including high costs, technical complexity, and the need for long-term clinical validation remain. Overall, DSD represents a significant advancement toward a more precise, patient-centered, and digitally driven approach in modern esthetic dentistry.