Biodiesel has become one of the most attractive alternative biofuels as a sustainable option for petroleum-derived diesel fuel. This research presents an innovative method for producing biodiesel from a non-edible plant source, Wild Samara (Sisymbrium orientale) seeds oil (SOSO), which is abundant in many countries. Production process was carried out via a transesterification reaction using two types of catalysts: a homogeneous KOH-based catalyst and a heterogeneous silica-supported calcium oxide (CaO-SiO₂) catalyst. CaO was prepared from eggshells, while silica was extracted from peanut shells. The catalyst was characterized using various analytical techniques such as FT-IR, FESEM, and XRD. Novelty of this study lies in its focus on improving production by examining the factors affecting biodiesel yield, including the ethanol-to-oil molar ratio, catalyst type and quantity, reaction temperature, and reaction time. Results indicated that maximum biodiesel yield reached (94.2%) when using (KOH) as catalyst, whereas higher yield of (98.5%) was achieved with heterogeneous catalyst. Optimal molar ratio [ethanol: oil] was [6:1], and the optimal amount of KOH catalyst was 1.5wt.% and 1wt.% for CaO-SiO2. Optimal reaction temperature was 60°C, while ideal reaction time was 1.5 hr. for KOH and 1hr. for CaO-SiO2. for heterogeneous catalyst. Properties of produced fuel were analyzed using GC-MS and FT-IR techniques. Results showed that biodiesel produced using CaO-SiO₂ catalyst had excellent physical and chemical properties. Compared to its counterpart prepared using KOH, this study highlights potential for achieving one of sustainable development goals by exploiting non-food natural resources and organic waste to produce environmentally friendly biofuel.