Polyetheretherketone (PEEK) is a highperformance thermoplastic increasingly investigated for biomedical applications owing to its outstanding mechanical strength, chemical stability, and biocompatibility. Nevertheless, its inherent bioinert nature restricts osseointegration, necessitating reinforcement with bioactive phases. In the present study, nanohydroxyapatite (nHA) was incorporated into PEEK at 8, 16, and 24 wt.% and processed into composites via extrusion and 3D printing. The mechanical, tribological, and thermal responses of the resulting materials were systematically examined. Wear testing demonstrated that neat PEEK exhibited the lowest wear volume (0.05 mm³ at 2.5 km), while higher nHA contents led to increased wear, attributable to particle pull-out and induced brittleness. In contrast, hardness improved notably with reinforcement, achieving a maximum of 45 VHN at 16 wt.% nHA, signifying an optimum balance between strength and bioactivity. Differential Scanning Calorimetry (DSC) revealed negligible changes in thermal transitions, with Tg remaining stable at 152– 153 °C and Tm within 342–345 °C, confirming excellent thermal stability. Collectively, these findings highlight that PEEK–NHA composites, particularly at 16 wt.% loading, provide a superior combination of wear resistance, mechanical reliability, and thermal stability, making them highly promising candidates for orthopedic and dental implant applications.