Two experiments were conducted to evaluate the relative bioavailability (RBV) and performance effects of four zinc sources: zinc sulfate (ZnSO₄), zinc glycinate (ZnGly), zinc amino acid hydrate (ZnAAH), and zinc methionine hydroxy analog (ZnMHA) in male broilers. Experiment 1 used a depletion-repletion model with semi-purified diets to assess graded supplementation levels of ZnSO₄, ZnGly, and ZnAAH (0, 5, 10, 15, or 20 mg/kg). Experiment 2 evaluated all four sources at 10 and 60 mg/kg, along with a negative control (NC, 0 mg/kg), under practical corn-soybean meal feeding conditions. In Experiment 1, supplemental zinc significantly affected BWG, FI, FCR, and tibia zinc concentration. Growth responses (BWG and FI) exhibited both linear and quadratic trends, plateauing at approximately 11.7 mg/kg zinc intake, while tibia zinc increased linearly across all levels. Organic sources (ZnGly and ZnAAH) increased tibia zinc by 11-12% and improved FCR by 1.1-1.5 points compared with ZnSO₄. RBV estimates based on tibia zinc indicated that ZnGly and ZnAAH were 42-48% more bioavailable than ZnSO₄ (P < 0.05), with no significant differences between the two organic sources. In Experiment 2, zinc source influenced BWG, FI, and FCR (P < 0.05) and tended to affect overall FCR (P = 0.07). Supplementation with ZnSO₄ and ZnGly increased overall BWG by 118 g and 104 g, respectively, compared with NC, and resulted in greater performance than ZnMHA. ZnGly reduced overall FCR by 3.6 points, while ZnGly and ZnSO₄ improved adjusted FCR by 6.8 and 5.8 points, respectively, relative to NC (P < 0.05). ZnGly increased hot carcass yield by 0.62% (P < 0.05), whereas ZnSO₄ and ZnMHA showed trends toward improvement (P < 0.10). Excreta zinc increased with supplementation across all sources, while tibia zinc increased for all treatments except ZnMHA compared with NC. Overall, organic zinc sources demonstrated greater RBV than ZnSO₄ under semi-purified conditions, primarily based on tibia zinc responses. However, under practical feeding conditions, ZnSO₄ and ZnGly produced comparable improvements in growth performance, suggesting that RBV estimates may not fully predict performance outcomes in commercial-type diets. Future research should focus on optimizing zinc strategies to enhance carcass yield and explore broader physiological roles, including footpad health, immunity, welfare, and environmental sustainability in commercial broiler production.