Nucleation plays a fundamental role in polymer crystallization, a critical process that influences the mechanical, thermal, and optical properties of polymeric materials. Understanding nucleation is essential for controlling crystallization behavior, improving material performance, and optimizing industrial processing. Nucleation of Polymers: Crystallization Fundamentals and Applications provides a comprehensive overview of the crystallization process, examining both heterogeneous and homogeneous nucleation in polymers and highlighting the role of selective nucleating agents, which are crucial additives that enhance the processability and performance of various thermoplastic polymers. The book is structured into three parts, beginning with foundational theories that cover essential concepts such as physical structure alignment, self-nucleation, and interactions with additives. The second part applies these theoretical insights to important polymer classes, including polyamides, polyesters, and bio-based thermoplastics, providing practical examples of nucleation in action. The final section addresses key aspects of processing and sustainability, including the effects of cooling and quenching on nucleation efficiency and the implications for property design and recycling. This is an invaluable resource for advanced students, researchers, scientists and engineers seeking to understand nucleation theory and practical polymer applications.