This review explores the role of polymer composites in 3D/4D printing, focusing on materials, advancements, and future prospects. It discusses the evolution of polymer 3D printing, highlighting the development of various polymer types, including thermoplastics, thermosets, elastomers, hydrogels, and shape memory polymers (SMPs). The review emphasizes the versatility of polymer materials in additive manufacturing, their adaptability, and applications across diverse industries. It also examines recent advancements in microvascular and encapsulation self-healing mechanisms, the potential of supramolecular polymers, and the progress in hybrid printing using polymer-metal and polymer-ceramic composites. The paper addresses challenges in the additive manufacturing of polymer composites and suggests future research directions in this rapidly evolving field. The review highlights the transformative impact of 4D printing, which introduces the dimension of time, enabling dynamic transformations in printed structures. It explores the use of smart polymers, such as SMPs, smart hydrogels, and liquid crystal elastomers (LCEs), in 4D printing, emphasizing their ability to respond to external stimuli and undergo shape transformations. The review also discusses the potential of self-healing polymer materials in 4D printing, which can autonomously repair defects and enhance the durability and functionality of printed structures. Overall, the review provides a comprehensive overview of the current state of polymer composites in 3D/4D printing, highlighting their significance in advancing additive manufacturing technologies.This review explores the role of polymer composites in 3D/4D printing, focusing on materials, advancements, and future prospects. It discusses the evolution of polymer 3D printing, highlighting the development of various polymer types, including thermoplastics, thermosets, elastomers, hydrogels, and shape memory polymers (SMPs). The review emphasizes the versatility of polymer materials in additive manufacturing, their adaptability, and applications across diverse industries. It also examines recent advancements in microvascular and encapsulation self-healing mechanisms, the potential of supramolecular polymers, and the progress in hybrid printing using polymer-metal and polymer-ceramic composites. The paper addresses challenges in the additive manufacturing of polymer composites and suggests future research directions in this rapidly evolving field. The review highlights the transformative impact of 4D printing, which introduces the dimension of time, enabling dynamic transformations in printed structures. It explores the use of smart polymers, such as SMPs, smart hydrogels, and liquid crystal elastomers (LCEs), in 4D printing, emphasizing their ability to respond to external stimuli and undergo shape transformations. The review also discusses the potential of self-healing polymer materials in 4D printing, which can autonomously repair defects and enhance the durability and functionality of printed structures. Overall, the review provides a comprehensive overview of the current state of polymer composites in 3D/4D printing, highlighting their significance in advancing additive manufacturing technologies.