Biodiesel production from Pongamia pinnata oil provides an alternative energy source for various uses. Fe3O4 was prepared by the co-precipitation method at 60°C and 400 rpm until it reached a thick consistency and dried in a hot air oven for 6 hours, maintaining the temperature at 150°C. The CaO was prepared from the mussel shells by the calcination method at 300°C to 800°C in a muffle furnace for 4 hours. The Nano catalyst ZrO2/CaO-Fe3O4 was prepared by doping. The prepared catalyst was characterized by FTIR, SEM, XRD and Particle size analysis to study its catalytic activity. It was transesterified using the ZrO2/CaO-Fe3O4 catalyst at various experimental conditions: 5% (w/w) catalyst concentration, 12:1% methanol to oil molar ratio, 65°C reaction temperature and 50 min of reaction time, at which a maximum biodiesel yield of 98.11 wt% was obtained. The fuel properties were analyzed using the ASTM D6751 standard. The prepared nanocatalyst seems to be highly active in terms of quality and efficiency.