The present study aims to investigate the effect of short carbon fiber (SCFs) and hydroxyapatite (HAp) content on mechanical, tribological, and biological properties of high-density polyethylene (HDPE) matrix composites. The proposed HDPE/SCFs-HAp hybrid composites with good mechanical-tribological behavior and biocompatibility might be used as novel implants in orthopedics. The composites were developed using twin-screw extrusion and compression molding methods. Hardness, tensile, and 3-point bending tests were performed to investigate the mechanical properties of hybrid composites. To evaluate wear performance of the samples, three different loads (10, 20, and 30 N) were applied in simulated body fluid. Biological activities of the hybrid composite samples were investigated. Results show that HDPE-10%SCFs-10%HAp sample provides optimum mechanical, tribological, and biological properties.