This study investigates the catalytic performance of raw kaolin and alkaline-modified kaolin (m-kaolin) as low-cost solid acid catalysts for biodiesel production via the esterification. The modification process, involving alkaline leaching with 2M NaOH, resulted in a delaminated and mesoporous structure with enhanced surface area (6.8 m²/g) and high acid density (521.1 μmol NH₃/g). Under optimized conditions (100 °C, 3 wt.% catalyst, 20:1 methanol-to-oil ratio, and 3 hours), the conversion efficiency increased from 81.97% for raw kaolin to 88.34% for m-kaolin. Kinetic studies confirmed that both catalysts follow pseudo-first-order kinetics, with the apparent rate constant (Kapp) increasing from 0.097 h⁻¹ (raw kaolin) to 0.127 h⁻¹ (m-kaolin). A reaction mechanism following the Eley-Rideal model was proposed, emphasizing the role of the enhanced acidic sites and mesoporous framework. These results underscore the potential of modified kaolin as a highly efficient catalyst that bridges the gap between natural minerals and engineered catalysts.