This comprehensive review explores the advancements and prospects of polymer composites in 3D/4D printing. It highlights the versatility and environmental adaptability of polymeric materials, including thermoplastics, thermosets, elastomers, and shape memory polymers (SMPs), such as liquid crystal elastomers (LCEs) and self-healing polymers. The review discusses recent advancements in microvascular and encapsulation self-healing mechanisms, the potential of supramolecular polymers, and the latest progress in hybrid printing using polymer-metal and polymer-ceramic composites. It also addresses the challenges faced in additive manufacturing of polymer composites and suggests avenues for future research. The evolution of polymer 3D printing is traced from its early stages to the current state, emphasizing the role of innovative materials and technologies in driving this field forward. The review concludes by offering insights into the transformative impact of polymer composites in 3D/4D printing across various industries, including engineering, healthcare, aerospace, and automotive.This comprehensive review explores the advancements and prospects of polymer composites in 3D/4D printing. It highlights the versatility and environmental adaptability of polymeric materials, including thermoplastics, thermosets, elastomers, and shape memory polymers (SMPs), such as liquid crystal elastomers (LCEs) and self-healing polymers. The review discusses recent advancements in microvascular and encapsulation self-healing mechanisms, the potential of supramolecular polymers, and the latest progress in hybrid printing using polymer-metal and polymer-ceramic composites. It also addresses the challenges faced in additive manufacturing of polymer composites and suggests avenues for future research. The evolution of polymer 3D printing is traced from its early stages to the current state, emphasizing the role of innovative materials and technologies in driving this field forward. The review concludes by offering insights into the transformative impact of polymer composites in 3D/4D printing across various industries, including engineering, healthcare, aerospace, and automotive.