The depletion of fossil fuels and growing environmental concerns necessitate the development of renewable biofuels. Blighia sapida seed oil, an inedible and underutilized resource, presents a viable option for biodiesel production. This study optimized its transesterification process using advanced modelling to improve yield and fuel quality. A two-step esterification–transesterification approach was used, with process variables, methanol-to-oil molar ratio (6:1–12:1), catalyst concentration (0.