Developing biofuel production technologies is a pressing problem for energy-deficient countries, including Ukraine. Traditional biodiesel production uses methanol, which is toxic and more expensive in the future due to dependence on natural gas. This study explores bioethanol’s potential application in the plant-based oils’ transesterification process to create an integrated bioethanol-biodiesel production system within a unified technological framework. An analysis of modern technologies for obtaining biodiesel, particularly transesterification, hydrogenation, esterification, and enzyme catalysis, was conducted. The investigation was performed through laboratory-scale simulation of the transesterification reaction between plant oils and bioethanol, employing alkaline catalysts including potassium hydroxide (KOH) and sodium hydroxide as reaction promoters. The influence of alcohol concentration, reaction temperature, and catalyst type on diesel biofuel yield and quality characteristics was studied. Spectroscopic analysis methods were used to determine the composition of the obtained esters and the glycerin fraction. According to the results of experimental studies, the optimal excess of bioethanol should be 30–45% of the stoichiometric amount, and the optimal process temperature is 20–30 ℃. When using traditional heterogeneous catalysts, the degree of conversion of oil into esters was 96.31%. In contrast, using a complex catalyst made it possible to reach 99.3%, close to the results for methyl alcohol (99.5%). It was found that when the reaction temperature increases above 45 ℃, the phase separation deteriorates, and the amount of soap in the product increases. The experimental findings demonstrate the feasibility of efficiently utilizing bioethanol as a viable agent for biodiesel synthesis. The introduction of the technology will contribute to increasing Ukraine’s energy independence, effective use of distillery capacities, and environmentally safer production of biofuels.