The potential of banana peels as a suitable catalyst for conversion of Bauhinia monandra seed oil (BMSO) to fatty acidy methyl ester (FAME) in a transesterification reaction was investigated. The FAME was produced through a two-step method of esterification and transesterification. The high free fatty acid (FFA) content of BMSO was reduced in the esterification reaction to less than 1% using reaction conditions of methanol/FFA molar ratio of 46:1, Fe2(SO4)3 of 12 wt.%, and reaction time of 75 min. The design of experiments (DoE) was applied in the transesterification step to investigate the effect of pertinent process parameters on the yield of BMME (Bauhinia monandra methyl esters). The results showed that BMME, which is consistent with ASTM D-6751 and EN 14214 standards, can be obtained at an optimum yield of 98.5 ± 0.18 wt.% using catalyst loading of 2.75 wt.%, methanol/oil molar ratio of 7.6:1 and reaction time of 69.02 min. FT-IR, XRD, SEM and elemental analysis revealed that the catalytic action of banana peels was as a result of the potassium content and the microstructural formation when calcined at 700 °C. The study revealed the possibility of developing heterogeneous catalyst from banana peels for FAME production, which may reduce the overall cost of production.