This review article provides an extensive overview of recent advancements in the recycling and upcycling of thermoset and thermoplastic polymers, focusing on their composite forms. For thermoset polymers, the emphasis is on fiber-reinforced polymer composites, particularly epoxy-based systems and carbon/glass fibers, due to their environmental concerns. Thermal processes (fluidized bed, pyrolysis) and chemical processes (solvolysis) are discussed, along with combined and extraordinary recycling techniques (microwave, steam, ultrasonic, electrochemical, biological, and ionic liquids). Mechanical recycling, which leads to material degradation, is excluded. Insights into upcycling methodologies for fiber reuse are also provided. For thermoplastic polymers, the most advanced recycling approaches for common polymer matrices are presented, along with appropriate additives for matrix upcycling. Mechanical, chemical, and enzymatic recycling processes are described, and recent achievements in the use of fiber-reinforced thermoplastic composites are highlighted. The review aims to serve as a guide for educational purposes, targeting students and technicians in polymer recycling.This review article provides an extensive overview of recent advancements in the recycling and upcycling of thermoset and thermoplastic polymers, focusing on their composite forms. For thermoset polymers, the emphasis is on fiber-reinforced polymer composites, particularly epoxy-based systems and carbon/glass fibers, due to their environmental concerns. Thermal processes (fluidized bed, pyrolysis) and chemical processes (solvolysis) are discussed, along with combined and extraordinary recycling techniques (microwave, steam, ultrasonic, electrochemical, biological, and ionic liquids). Mechanical recycling, which leads to material degradation, is excluded. Insights into upcycling methodologies for fiber reuse are also provided. For thermoplastic polymers, the most advanced recycling approaches for common polymer matrices are presented, along with appropriate additives for matrix upcycling. Mechanical, chemical, and enzymatic recycling processes are described, and recent achievements in the use of fiber-reinforced thermoplastic composites are highlighted. The review aims to serve as a guide for educational purposes, targeting students and technicians in polymer recycling.