Abstract <p>This study presents a simple, effective, inexpensive, and environmentally friendly method for synthesizing methyl salicylate via Fischer esterification using cation-exchanged montmorillonite (Mt) as a natural heterogeneous catalyst. Montmorillonite was modified with different cations to produce Mt–Co²⁺, Mt–Fe³⁺, Mt–Cr³⁺, and Mt–Fe²⁺. Characterization by X-ray powder diffraction (XRD) and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM–EDX) revealed that the cation-exchange process preserved the clay’s fundamental structure. The modified montmorillonite achieved higher conversions faster at milder temperatures, suggesting industrial catalytic potential. Methyl salicylate yields varied with the cation: Fe³⁺ (78%) and Cr³⁺ (77%) provided the highest yields, likely due to their stronger Lewis acidity, which enhances carbonyl group activation during esterification. These findings indicate that cation-exchanged montmorillonite holds promise as an industrial catalyst.</p>