Metallic-reinforced thermoplastic composites fabricated via fused deposition modeling (FDM) offer a sustainable and material-efficient pathway for achieving enhanced functional performance; however, challenges related to uniform particle dispersion and interfacial bonding remain critical. In this study, the processing– structure–property correlation of AA2024 metal powder-reinforced polyethylene terephthalate glycol (PETG) composites was systematically investigated. Composite filaments containing 0–7.5 wt.% AA2024 were fabricated and processed under varying parameters, including layer height, infill density, and nozzle temperature. The resulting mechanical properties—tensile, flexural, and compressive strengths— along with wear behavior were evaluated, supported by microstructural characterization using scanning electron microscopy and energy-dispersive spectroscopy. The results revealed that an optimal reinforcement content of 5 wt.% AA2024 led to improvements of 19.8%, 17.6%, and 20.2% in tensile, flexural, and compressive strengths, respectively, accompanied by a significant reduction in wear rate of 40.5%. The enhanced performance is attributed to improved load transfer and microstructural integrity at optimal dispersion levels. Furthermore, a hybrid multi-criteria decision-making framework based on the analytical hierarchy process– technique for order preference by similarity to ideal solution (AHP–TOPSIS) was employed to identify the optimal processing conditions. The developed composite system demonstrates potential for efficient material utilization and advanced additive manufacturing applications, which are consistent with sustainable development goals.