The rate of Soybean (Glycine max) oil (SBO) extraction with a ternary solvent mixture (water, ethanol, and ethyl acetate) optimised with I-optimal Design (IOD) under the Mixture Methodology of the Design Expert (12.0.1.0). The data obtained were analysed statistically. The effect of extraction time (60-180 mins) and temperature (65-70 °C) on SBO was investigated and data obtained were used to evaluate the suitable kinetic and thermodynamic properties of the extraction. The maximum Rate of Oil Yield (32.35 mg/min) was achieved at the solvent mixture of 9.17% water, 6.67% ethanol, and 84.17% ethyl acetate. The Quadratic model best describes the Rate of Oil Yield, with a correlation coefficient (R2) of 0.9922 and an Adjusted R2 of 0.9825. The rate equation for the extraction process is a first-order reaction with ‘n’ value of 1.12756 (≅1.000) while the activation energy (Ea) and Arrhenius constant were 6508.1 kJ/mol and 38.901 s-1, respectively. The study has demonstrated the suitability of I-Optimal Design for the investigation of the Rate of Oil Yield from soybean and the result could be employed in oil extraction process design.