This review examines the mechanical performance of recycled 3D printed sustainable polymer-based composites, focusing on their application in additive manufacturing (AM). The study highlights the importance of recycling and reusing materials to align with the EU's Green Deal goals for sustainable circular economy models. It discusses the challenges and opportunities of using recycled materials in AM, emphasizing the need for improved mechanical properties and recyclability. The review covers various recycled materials, including plastics, metals, and ceramics, and evaluates their performance in AM processes. It also addresses the mechanical properties of these materials, such as tensile strength, impact resistance, and thermal stability, and discusses the effects of different processing techniques on their performance. The study identifies gaps in research, particularly in the use of dynamic mechanical analysis and impact testing for evaluating the performance of these composites. It concludes that further research is needed to optimize the mechanical properties of recycled materials for sustainable AM applications. The review also highlights the potential of using recycled materials in AM to reduce environmental impact and promote sustainable production. The study emphasizes the importance of life cycle assessment (LCA) in evaluating the environmental footprint of these materials and processes. Overall, the review provides a comprehensive overview of the current state of research on recycled 3D printed sustainable polymer-based composites and their potential for sustainable manufacturing.This review examines the mechanical performance of recycled 3D printed sustainable polymer-based composites, focusing on their application in additive manufacturing (AM). The study highlights the importance of recycling and reusing materials to align with the EU's Green Deal goals for sustainable circular economy models. It discusses the challenges and opportunities of using recycled materials in AM, emphasizing the need for improved mechanical properties and recyclability. The review covers various recycled materials, including plastics, metals, and ceramics, and evaluates their performance in AM processes. It also addresses the mechanical properties of these materials, such as tensile strength, impact resistance, and thermal stability, and discusses the effects of different processing techniques on their performance. The study identifies gaps in research, particularly in the use of dynamic mechanical analysis and impact testing for evaluating the performance of these composites. It concludes that further research is needed to optimize the mechanical properties of recycled materials for sustainable AM applications. The review also highlights the potential of using recycled materials in AM to reduce environmental impact and promote sustainable production. The study emphasizes the importance of life cycle assessment (LCA) in evaluating the environmental footprint of these materials and processes. Overall, the review provides a comprehensive overview of the current state of research on recycled 3D printed sustainable polymer-based composites and their potential for sustainable manufacturing.