Catalysts can increase the reaction rate in biodiesel synthesis. The biodiesel synthesis from used cooking oil (low-grade oil, LGO), green CaO from eggshell as a solid catalyst support is potential to be used as a catalyst in a one-step esterification-transesterification reaction. This study aims to utilize a solid catalyst supported by CaO prepared from activated chicken egg shells with KOH solution and loading TiO2/H for biodiesel synthesis from LGO in a one-step reaction and its reused. The solid catalyst of CaO/K-TiO2/H was characterized by active sites functional groups, crystallinity, and surface morphology as well as tested for synthesizing biodiesel from LGO. Results showed that the biodiesel yield using fresh catalyst was 93.89%, 78.24% for reused-1 catalyst, and 60.98% for reused-2 catalyst. The solid catalyst of CaO/K-TiO2/H had the potential to be developed for the synthesis of biodiesel from LGO in one-step process and can be reused.