Renewable and environmentally friendly fuels such as green diesel are increasingly important to ensure energy security and maintain ecological balance. This study reports the synthesis of cobalt catalysts supported on activated natural zeolite for application in the catalytic hydrodeoxygenation of jatropha oil to produce green diesel. The catalysts were prepared by wet impregnation with varying cobalt loadings (5, 10, and 15 wt%) and characterized by XRD, SAA, NH3-TPD, and SEM-EDX. The XRD patterns confirmed the presence of cobalt phases along with the crystalline framework of zeolite at all cobalt loadings. Increasing cobalt loading led to a decrease in surface area and acidity of the catalysts. The Co(10)/HZ catalyst exhibited the best performance, achieving 100% conversion, 79.34% liquid yield, and 94.98% selectivity to green diesel. These results indicate that Co(10)/HZ is a promising catalyst for green diesel production from jatropha oil. © 2026 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license. http://creativecommons.org/licenses/by-nc-nd/4.0/