This study reports the exploitation of Garden cress Lepidium sativum L. seed as a novel non-edible raw feedstock for producing high yield and quality biodiesels vial the optimized alcoholysis reaction. The satisfactory oil content of the Garden cress seeds (28.50± 1.50 % w/w) encouraged its utilization for biodiesel (BD) creation. The garden cress seed oil (GCSO) was transesterified with ethanol and a blend of methanol and ethanol via optimized alkali-catalyzed alcoholysis reaction. The typical reaction conditions, which resulted in the maximum yield of the ethylic BD (90.45 ± 2.0 % were 1.0 wt.% KOH, 8:1 ethanol: GCSO molar ratio, 65 ℃ for a duration of 75 minutes, while 0.80 wt.% KOH, 6:1 mixed alcohols: GCSO molar ratio, 60 ℃, and a duration of 1h, were the typical experimental conditions, which produced the superlative yield of MEBD (97.50± 1.50%,). Transformation of the GCSO to its corresponding alkyl esters was certified through the FTIR, 1 H NMR, and thinlayer chromatography studies. Besides, fuel properties of the pristine GCSO have noticeably changed and obeyed the ASTM criteria as a result of the alcoholysis reaction of GCSO with the said alcohols. Blends prepared by blending BD samples with petro diesel at various ratios (v/v) exhibited their compatibility with the specifications fixed by the ASTM standards. The alcoholysis reaction of the GCSO obeyed the first-order kinetics with activation energy values of 30.71 kJ/mol for the ethanolysis of the GCSO, and 32.93 kJ/mol for the transesterification with mixed methanol/ethanol alcohols. This study disclosed that the GCSO possessed the potential to be utilized as a successful alternative to petroleum-based diesel.