<p>A novel, precise, robust, and stability-indicating instrumental thin-layer chromatography (TLC) method was developed and validated for the quantitative estimation of tegoprazan in its marketed tablet formulation (Ki-CAB, 50&#xa0;mg). Chromatographic separation was achieved using TLC silica gel 60 F₂₅₄ glass plates and a mobile phase comprising toluene–ethyl acetate–ethanol–ammonia (70:20:10:0.1, <i>V/V</i>). Detection was performed densitometrically at 224&#xa0;nm. The optimized method produced a sharp, symmetrical peak for tegoprazan with an <i>R</i>_F value of 0.30 ± 0.02. The method was developed in compliance with the International Council for Harmonisation (ICH) Q2(R2) and ICH Q14 guidelines to achieve the desired analytical target profile—ensuring drug quantification with an accuracy of ± 2% and precision (RSD &lt; 2%), while maintaining clear resolution between the analyte and its degradation products. The validated method demonstrated acceptable linearity (100–800&#xa0;ng/band, <i>R</i>² = 0.9994), high precision (%RSD &lt; 2%), and satisfactory recovery (98.4%). The robustness of the method was confirmed by deliberate variations in mobile phase composition, saturation time, and volume. Forced degradation studies under acidic, alkaline, neutral, oxidative, thermal, and photolytic stress conditions confirmed the stability-indicating nature of the method, with distinct degradation peaks observed in each case. The method was also found to be specific with no interference from formulation excipients. Comparative assessment with existing chromatographic methods highlights the advantages of instrumental TLC in terms of simplicity, speed, cost-efficiency, and minimal solvent use—making it a green and practical alternative for routine quality control. The present work represents a novel instrumental TLC method for tegoprazan, and it demonstrates strong potential for implementation in pharmaceutical quality assurance.</p>