ABSTRACT The growing demand for sustainable, autonomous wearable electronics has spurred significant interest in piezoelectric materials capable of harvesting biomechanical energy from human motion. Piezoelectric energy harvesting offers a promising alternative to traditional battery‐powered systems, enabling continuous operation of wearable devices in healthcare, fitness monitoring, communication, and human‐machine interfacing. This review presents a detailed examination of the evolution, material design, and multifunctional applications of piezoelectric materials in wearable energy harvesting systems. The discussion begins with an overview of the fundamental principles of piezoelectricity and advances in material development, including ceramics, polymers, and composite structures that enhance electromechanical performance, flexibility, and biocompatibility. Particular attention is given to the integration of piezoelectric components into flexible substrates, textiles, and implantable devices, highlighting recent innovations in fabrication techniques such as electrospinning, 3D printing, and spray‐coating. The review further explores key application domains, including real‐time health monitoring, smart clothing, sports and fitness tracking, wearable communication systems, and intuitive human‐machine interfaces. Challenges related to energy output under low‐frequency human motion, long‐term durability, device integration, and material sustainability are critically evaluated. Additionally, the potential of hybrid energy harvesting systems and biodegradable piezoelectric materials is discussed in the context of next‐generation wearable technologies. By synthesizing recent progress and identifying emerging trends, this review provides strategic insights for researchers and developers working toward the realization of high‐efficiency, self‐powered wearable electronics.